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sys: fix, allow odd magic offsets to work as expected

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Created using this scriptlet:

sed -i -re 's/\(\(int \*\)newboot\)\[([0-9A-Fa-fxX]+)\/sizeof\(int\)\]/\*\(int \*\)\(\&newboot\[\1\]\)/g' sys/sys.c
This commit is contained in:
E. C. Masloch 2024-02-07 00:53:30 +01:00 committed by Kenneth J Davis
parent fc3032deb7
commit 1cd4a75e98
1 changed files with 8 additions and 8 deletions
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16
sys/sys.c
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@ -1656,12 +1656,12 @@ void put_boot(SYSOptions *opts)
if (opts->kernel.stdbs)
{
/* magic offset: loadsegoff_60 */
int defaultload = ((int *)newboot)[0x78/sizeof(int)];
int defaultload = *(int *)(&newboot[0x78]);
if (defaultload != 0x60 && defaultload != 0x70) {
printf("%s: Internal error: FAT32 load seg unexpected content\n", pgm);
exit(1);
}
((int *)newboot)[0x78/sizeof(int)] = opts->kernel.loadaddr;
*(int *)(&newboot[0x78]) = opts->kernel.loadaddr;
bsBiosMovOff = 0x82; /* magic offset: mov byte [bp + 40h], dl */
}
else /* compatible bs */
@ -1702,14 +1702,14 @@ void put_boot(SYSOptions *opts)
if (opts->kernel.stdbs)
{
/* magic offset: loadsegoff_60 */
int defaultload = ((int *)newboot)[0x5C/sizeof(int)];
int defaultload = *(int *)(&newboot[0x5C]);
if (defaultload != 0x60 && defaultload != 0x70) {
printf("%s: Internal error: FAT1%c load seg unexpected content\n",
pgm, fs == FAT12 ? '2' : '6');
exit(1);
}
/* this sets the segment we load the kernel to, default is 0x60:0 */
((int *)newboot)[0x5c/sizeof(int)] = opts->kernel.loadaddr;
*(int *)(&newboot[0x5C]) = opts->kernel.loadaddr;
bsBiosMovOff = 0x66; /* magic offset: mov byte [bp + 24h], dl */
}
else
@ -1719,12 +1719,12 @@ void put_boot(SYSOptions *opts)
/* this however changes the offset jumped to default 0x70:0 */
if (fs == FAT12) {
/* magic offset: jmp LOADSEG:xxxxh */
defaultload = ((int *)newboot)[0x11A/sizeof(int)];
((int *)newboot)[0x11A/sizeof(int)] = opts->kernel.loadaddr;
defaultload = *(int *)(&newboot[0x11A]);
*(int *)(&newboot[0x11A]) = opts->kernel.loadaddr;
} else {
/* magic offset: jmp LOADSEG:xxxxh */
defaultload = ((int *)newboot)[0x118/sizeof(int)];
((int *)newboot)[0x118/sizeof(int)] = opts->kernel.loadaddr;
defaultload = *(int *)(&newboot[0x118]);
*(int *)(&newboot[0x118]) = opts->kernel.loadaddr;
}
if (defaultload != 0x0 && defaultload != 0x200) {
printf("%s: Internal error: OEM FAT1%c load ofs unexpected content\n",