mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
73 lines
1.8 KiB
73 lines
1.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* -*- linux-c -*- ------------------------------------------------------- * |
|
* |
|
* Copyright (C) 1991, 1992 Linus Torvalds |
|
* Copyright 2007 rPath, Inc. - All Rights Reserved |
|
* Copyright 2009 Intel Corporation; author H. Peter Anvin |
|
* |
|
* Original APM BIOS checking by Stephen Rothwell, May 1994 |
|
* ([email protected]) |
|
* |
|
* ----------------------------------------------------------------------- */ |
|
|
|
/* |
|
* Get APM BIOS information |
|
*/ |
|
|
|
#include "boot.h" |
|
|
|
int query_apm_bios(void) |
|
{ |
|
struct biosregs ireg, oreg; |
|
|
|
/* APM BIOS installation check */ |
|
initregs(&ireg); |
|
ireg.ah = 0x53; |
|
intcall(0x15, &ireg, &oreg); |
|
|
|
if (oreg.flags & X86_EFLAGS_CF) |
|
return -1; /* No APM BIOS */ |
|
|
|
if (oreg.bx != 0x504d) /* "PM" signature */ |
|
return -1; |
|
|
|
if (!(oreg.cx & 0x02)) /* 32 bits supported? */ |
|
return -1; |
|
|
|
/* Disconnect first, just in case */ |
|
ireg.al = 0x04; |
|
intcall(0x15, &ireg, NULL); |
|
|
|
/* 32-bit connect */ |
|
ireg.al = 0x03; |
|
intcall(0x15, &ireg, &oreg); |
|
|
|
boot_params.apm_bios_info.cseg = oreg.ax; |
|
boot_params.apm_bios_info.offset = oreg.ebx; |
|
boot_params.apm_bios_info.cseg_16 = oreg.cx; |
|
boot_params.apm_bios_info.dseg = oreg.dx; |
|
boot_params.apm_bios_info.cseg_len = oreg.si; |
|
boot_params.apm_bios_info.cseg_16_len = oreg.hsi; |
|
boot_params.apm_bios_info.dseg_len = oreg.di; |
|
|
|
if (oreg.flags & X86_EFLAGS_CF) |
|
return -1; |
|
|
|
/* Redo the installation check as the 32-bit connect; |
|
some BIOSes return different flags this way... */ |
|
|
|
ireg.al = 0x00; |
|
intcall(0x15, &ireg, &oreg); |
|
|
|
if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) { |
|
/* Failure with 32-bit connect, try to disconnect and ignore */ |
|
ireg.al = 0x04; |
|
intcall(0x15, &ireg, NULL); |
|
return -1; |
|
} |
|
|
|
boot_params.apm_bios_info.version = oreg.ax; |
|
boot_params.apm_bios_info.flags = oreg.cx; |
|
return 0; |
|
} |
|
|
|
|