Hello! GRUB provides ability to pass APM BIOS data to payload as well as to show it to user via "lsapm" command. Pointed data is obtained via grub_apm_get_info function which in turn calls INT 0x15 AH 0x53 BIOS service routine. BIOS returns data via CPU registers and then received data is being scattered into fields of grub_apm_info struct.
According to APM BIOS spec v.1.2 low part of ESI register contains cseg_len value and high part of this register contains cseg_16_len value. But in current implementation of grub_apm_get_info function these we have reverse assignment, i.e. low part of ESI is assigned to cseg_16_len and high part is assigned to cseg_len. The following diff contains bug fix: diff --git a/grub-core/commands/i386/pc/lsapm.c b/grub-core/commands/i386/pc/lsapm.c index c82476d..d1c699b 100644 --- a/grub-core/commands/i386/pc/lsapm.c +++ b/grub-core/commands/i386/pc/lsapm.c @@ -59,8 +59,8 @@ grub_apm_get_info (struct grub_apm_info *info) info->offset = regs.ebx; info->cseg_16 = regs.ecx & 0xffff; info->dseg = regs.edx & 0xffff; - info->cseg_len = regs.esi >> 16; - info->cseg_16_len = regs.esi & 0xffff; + info->cseg_len = regs.esi & 0xffff; + info->cseg_16_len = regs.esi >> 16; info->dseg_len = regs.edi; return 1; -- With Best regards, Vladimir Andreev _______________________________________________ Bug-grub mailing list Bug-grub@gnu.org https://lists.gnu.org/mailman/listinfo/bug-grub
