OS_Develop/FreeDOS
OS_Develop/FreeDOS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

From bzt, initialize drive parameter head & sector values to avoid potential divisions by 0

Browse Source
This commit is contained in:
Kenneth J Davis 2023-12-08 21:20:46 -05:00
parent 5880d36ba9
commit f1249dcd6f
No known key found for this signature in database
GPG Key ID: 59D5F216C38F11FD
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
kernel/initdisk.c
View File

@ -723,8 +723,13 @@ StandardBios: /* old way to get parameters */
init_call_intr(0x13, &regs);
if (regs.flags & 0x01)
if (regs.flags & 0x01)
{
/* to avoid division by zero later, use some sane defaults */
driveParam->chs.Head = 16;
driveParam->chs.Sector = 63;
goto ErrorReturn;
}
/* int13h call returns max value, store as count (#) i.e. +1 for 0 based heads & cylinders */
driveParam->chs.Head = (regs.d.x >> 8) + 1; /* DH = max head value = # of heads - 1 (0-255) */