Stockage CHS

<h1 style="margin: 12pt 0pt 6pt 21.6pt; text-align: justify;"><span style="font-family: arial;"><b><span style="font-size: large;">Décodage stockage CHS</span></b></span></h1><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Dans le billet précédent, nous avons avec la commande od affiché une table de partitions et nous en avons expliqué le contenu, mis à part certaines zones qui ont été ignorées. Il s'agit des zones où  sont enregistrées les données CHS (Cylindre,Tête, Secteur) relatives au début et à la fin des partitions.</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Nous allons expliquer comment décoder les données CHS que l'on peut trouver dans une table de partitions.</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Affichons avec od la table de partitions du disque utilisé comme exemple:</span></div><div style="background-color: #e6e6ff; font-family: Courier New,monospace; line-height: 1em;"><span style="font-size: medium;"># od -Ad -tx1 -j 446 -N 66 /dev/sda</span><br /><span style="font-size: medium;">0000446 00 </span><span style="background-color: #ffcc99;"><span style="font-size: medium;">01 01 00</span></span><span style="font-size: medium;"> 0b </span><span style="color: blue;"><span style="background-color: #cccccc;"><b><span style="font-size: medium;">ef bf 5e</span></b></span></span><span style="font-size: medium;"> 3f 00 00 00 b1 0a 8c 00  </span><br /><span style="font-size: medium;">0000462 80 </span><span style="color: blue;"><span style="background-color: #ffcc99;"><b><span style="font-size: medium;">01 81 5f</span></b></span></span><span style="font-size: medium;"> 07 </span><span style="background-color: #cccccc;"><span style="font-size: medium;">ef ff ff</span></span><span style="font-size: medium;"> 2f 0b 8c 00 d1 47 1c 04  </span><br /><span style="font-size: medium;">0000478 00 </span><span style="background-color: #ffcc99;"><span style="font-size: medium;">ef ff ff</span></span><span style="font-size: medium;"> 83 </span><span style="background-color: #cccccc;"><span style="font-size: medium;">ef ff ff</span></span><span style="font-size: medium;"> 00 53 a8 04 10 3b 00 00  </span><br /><span style="font-size: medium;">0000494 00 </span><span style="background-color: #ffcc99;"><span style="font-size: medium;">00 00 00</span></span><span style="font-size: medium;"> 00 </span><span style="background-color: #cccccc;"><span style="font-size: medium;">00 00 00</span></span><span style="font-size: medium;"> 00 00 00 00 00 00 00 00  </span><br /><span style="font-size: medium;">0000510 55 aa  </span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">La colonne 1 de la table nous indique que la partition sda2 est marquée comme étant amorçable.</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">La colonne 5 nous apprend que:</span></div><div style="font-family: Arial; margin: 0pt;"><span style="font-size: medium;">sda 1 est une partition FAT 32</span><br /><span style="font-size: medium;">sda2 est une partition NTFS</span><br /><span style="font-size: medium;">sda3 est une partition linux</span></div><div style="font-family: Arial; margin: 0pt;"><span style="font-size: medium;">(Voir billet précédent).</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Le secteur qui contient cette table de partition est le secteur 0 du disque: il se trouve sur le cylindre 0 et est lu par la tête 0. Cependant dans le système d'adressage CHS, les secteurs sont comptés à partir de 1.</span></div><div style="font-family: Arial; margin: 0pt;"><span style="font-size: medium;">Son adresse CHS est donc</span></div><div style="font-family: Arial; margin: 0pt;"><span style="font-size: medium;">CHS=(0,0,1) </span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Pour les autres adresses CHS, nous allons maintenant considérer les colonnes sur fond orange (données CHS du début de la partition) et sur fond gris (données CHS de fin de la partition).</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Le premier octet se rapporte à la tête, les deux suivant à l'ensemble secteur cylindre.</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Ainsi pour le début de la partition 1, il semble évident que:</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">CHS=(0,1,1)</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Ce n'est pas faux, mais en fait, c'est un peu plus compliqué que cela.</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">En effet si l</span><span style="color: black;"><span style="font-size: medium;">e premier octet donne le numéro de la tête,  dans le deuxième octet, seuls les bits 0 à 5 correspondent au  numéro du secteur. Les bits 6 et 7  constituent les bits supérieurs (8 et 9) du numéro de cylindre. Le numéro de cylindre est donc </span></span><span style="color: black;"><b><span style="font-size: medium;">un nombre à 10 bits dont le maximum est 1023</span></b></span><span style="color: black;"><span style="font-size: medium;">.</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Le tableau suivant montre ce qu'il en est pour le stockage des données relatives à la fin de la partition sda1:</span></span></div><div style="margin: 0pt; text-align: justify;"><br /></div><table border="1" bordercolor="#666666" cellpadding="0" cellspacing="0" style="margin-left: 0pt;"><tbody><tr><td colspan="8" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Tête</span></b></span></span></div></td><td colspan="16" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Secteur Cylindre</span></b></span></span></div></td></tr><tr><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">E</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">F</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">B</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">F</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">5</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">E</span></b></span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">1</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">0</span></span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">7</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">6</span></span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr></tbody></table><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">La ligne 2 du tableau reprend les données en hexadécimal provenant de la table de partitions, la ligne 3 reprend les mêmes données en binaire. En ligne 4, on trouve la numérotation des bits.</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Les bits sur fond jaune se rapport au numéro de cylindre, les bits sur fond vert au numéro de secteur.</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Réorganisons le tableau de manière à mettre ensemble les bits qui constituent le numéro de cylindre:</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><br /></div><table border="1" bordercolor="#666666" cellpadding="0" cellspacing="0" style="margin-left: 0pt;"><tbody><tr><td colspan="8" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Tête</span></b></span></span></div></td><td colspan="6" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Secteur</span></b></span></span></div></td><td colspan="10" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Cylindre</span></b></span></span></div></td></tr><tr><td colspan="4" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">E</span></b></span></span></div></td><td colspan="4" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">F</span></b></span></span></div></td><td colspan="2" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">3</span></b></span></span></div></td><td colspan="4" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">F</span></b></span></span></div></td><td colspan="2" style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">2</span></b></span></span></div></td><td colspan="4" style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">5</span></b></span></span></div></td><td colspan="4" style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">E</span></b></span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">1</span></span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">0</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><br /></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">9</span></span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">8</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr><tr><td colspan="8" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">239</span></span></div></td><td colspan="6" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">63</span></span></div></td><td colspan="10" style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">606</span></span></div></td></tr></tbody></table><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">(On a ajouté au tableau une 5</span></span><span style="color: black;">^{<span style="font-size: xx-small;">ième</span>}</span><span style="vertical-align: baseline;"><span style="color: black;"><span style="font-size: medium;"> ligne qui donne l'équivalent en décimal des nombres hexadécimaux de même couleur).</span></span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">L'adresse CHS de la fin de la partition est donc:</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">CHS=(606,239,63)</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Dessinons des tableaux du même genre pour rechercher l'adresse CHS du début de sda2:</span></span></div><div style="font-family: Verdana; margin: 0pt; text-align: justify;"><br /></div><table border="1" bordercolor="#666666" cellpadding="0" cellspacing="0" style="margin-left: 0pt;"><tbody><tr><td colspan="8" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Tête</span></b></span></span></div></td><td colspan="16" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Secteur Cylindre</span></b></span></span></div></td></tr><tr><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">0</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">1</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">8</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">1</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">5</span></b></span></span></div></td><td colspan="4" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: blue;"><b><span style="font-size: medium;">F</span></b></span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">1</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">0</span></span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: middle;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">7</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">6</span></span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr></tbody></table><div style="margin: 0pt; text-align: justify;"><br /></div><table border="1" bordercolor="#666666" cellpadding="0" cellspacing="0" style="margin-left: 0pt;"><tbody><tr><td colspan="8" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Tête</span></b></span></span></div></td><td colspan="6" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Secteur</span></b></span></span></div></td><td colspan="10" style="vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">Cylindre</span></b></span></span></div></td></tr><tr><td colspan="4" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">0</span></b></span></span></div></td><td colspan="4" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">1</span></b></span></span></div></td><td colspan="2" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">0</span></b></span></span></div></td><td colspan="4" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">1</span></b></span></span></div></td><td colspan="2" style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">2</span></b></span></span></div></td><td colspan="4" style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">5</span></b></span></span></div></td><td colspan="4" style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: black;"><b><span style="font-size: medium;">F</span></b></span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">1</span></span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">0</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td></tr><tr><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">9</span></span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="color: red;"><span style="font-size: medium;">8</span></span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">7</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">6</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">5</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">4</span></span></div></td><td style="background-color: #e6ff00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">3</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">2</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">0</span></span></div></td></tr><tr><td colspan="8" style="background-color: #ffcc99; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td colspan="6" style="background-color: #00ae00; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">1</span></span></div></td><td colspan="10" style="background-color: yellow; vertical-align: top;"><div style="margin: 0pt; text-align: center;"><span style="font-family: 'liberation mono';"><span style="font-size: medium;">607</span></span></div></td></tr></tbody></table><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">On trouve:</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">CHS=(607,1,1)</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Les autres données CHS qui figurent dans la table de partition étudiée sont toutes égales à EF</span></span> <span style="color: black;"><span style="font-size: medium;">FF</span></span> <span style="color: black;"><span style="font-size: medium;">FF</span></span> <span style="color: black;"><span style="font-size: medium;">FF ce qui donne des numéros de cylindre valant tous 3FF (1023). Ces données ne sont donc d'aucune utilité pour établir des adresses CHS.</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Cependant, il existe des formules permettant de calculer l'adresse CHS à partir du système d'adressage LBA (Logical Block Adress) dans lequel les N blocs logiques d'un disque sont numérotés de 0 à N</span></span><span style="color: black;"><span style="font-size: medium;">‑</span></span><span style="color: black;"><span style="font-size: medium;">1. Les blocs logiques sont ici identiques aux secteurs et l'adresse LBA du début des partitions est celle qui figure dans la table de partitions occupant les colonnes 9 à 12. Pour l'adresse de fin, il suffit d'ajouter la taille (en secteurs) moins 1. Si A désigne l'adresse LBA, NS le nombre de secteurs par piste et NT le nombre de têtes, les formules sont les suivantes:</span></span></div><div style="font-family: Arial; margin: 0pt;"><span style="font-size: medium;">S = ( A % NS ) + 1</span><br /><span style="font-size: medium;">H = ( A - S + 1 ) / NS % NT</span><br /><span style="font-size: medium;">C = ( A - S + 1 ) / NS / NT</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">(% est l'opérateur modulo)</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Pour notre disque exemple NS=63 et NT=240</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Calculons l'adresse CHS de la fin de la partition sda1, pour vérifier si on retrouve bien les valeurs directement lues dans la table des partitions.</span></span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Rappelons que les adresses en secteurs (en blocs logiques) des partitions se présentent dans la table de partitions sous forme d'un nombre hexadécimal de 32 bits au format little-endian. Idem pour les tailles qui elles se trouvent aux colonnes 13 à 16. On pourrait convertir ces adresses et ces tailles en nombre décimal, ou même les afficher directement sous ce format à l'aide de od (voir billet précédent), mais la puissance extraordinaire de la ligne de commande linux fait qu'il n'est même pas nécessaire d'effectuer ces conversions:</span></span></div><div style="background-color: #e6e6ff; font-family: Courier New; margin: 0pt;"><span style="font-size: medium;">$ A=$((0x3f+0x8c0ab1-1))</span><br /><span style="font-size: medium;">$ S=$(((A%NS)+1))</span><br /><span style="font-size: medium;">$ H=$(((A-S+1)/NS%NT))</span><br /><span style="font-size: medium;">$ C=$(((A-S+1)/NS/NT))</span><br /><span style="font-size: medium;">$ echo $C,$H,$S</span><br /><span style="font-size: medium;">606,239,63</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="color: black;"><span style="font-size: medium;">Procédons de même pour la fin de la partition sda2:</span></span></div><div style="background-color: #e6e6ff; font-family: Courier New; margin: 0pt;"><span style="font-size: medium;">A=$((0x8c0b2f+0x41c47d1-1))</span><br /><span style="font-size: medium;">$ S=$(((A%NS)+1))</span><br /><span style="font-size: medium;">$ H=$(((A-S+1)/NS%NT))</span><br /><span style="font-size: medium;">$ C=$(((A-S+1)/NS/NT))</span><br /><span style="font-size: medium;">$ echo $C,$H,$S</span><br /><span style="font-size: medium;">5167,239,63</span></div><div style="font-family: Arial; margin: 0pt; text-align: justify;"><span style="font-size: medium;">Ces dernières valeurs ne peuvent pas être stockées dans la tables de partitions à l'emplacement prévu, puisque le numéro du cylindre est supérieur à 1023.</span></div>

Stockage CHS

Décodage stockage CHS Dans le billet précédent, nous avons avec la commande od affiché une table de partitions et nous en avons expliqué le ...

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