/* Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <realmode.h>
#include <biosint.h>
/** Assembly routine in inline asm */
extern void int15_fakee820();
/** Original INT 15 handler */
static struct segoff __text16 ( real_int15_vector );
#define real_int15_vector __use_text16 ( real_int15_vector )
/** An INT 15,e820 memory map entry */
struct e820_entry {
/** Start of region */
uint64_t start;
/** Length of region */
uint64_t len;
/** Type of region */
uint32_t type;
} __attribute__ (( packed ));
#define E820_TYPE_RAM 1 /**< Normal memory */
#define E820_TYPE_RSVD 2 /**< Reserved and unavailable */
#define E820_TYPE_ACPI 3 /**< ACPI reclaim memory */
#define E820_TYPE_NVS 4 /**< ACPI NVS memory */
/** Fake e820 map */
static struct e820_entry __text16_array ( e820map, [] ) __used = {
{ 0x00000000ULL, ( 0x000a0000ULL - 0x00000000ULL ), E820_TYPE_RAM },
{ 0x00100000ULL, ( 0xcfb50000ULL - 0x00100000ULL ), E820_TYPE_RAM },
{ 0xcfb50000ULL, ( 0xcfb64000ULL - 0xcfb50000ULL ), E820_TYPE_RSVD },
{ 0xcfb64000ULL, ( 0xcfb66000ULL - 0xcfb64000ULL ), E820_TYPE_RSVD },
{ 0xcfb66000ULL, ( 0xcfb85c00ULL - 0xcfb66000ULL ), E820_TYPE_ACPI },
{ 0xcfb85c00ULL, ( 0xd0000000ULL - 0xcfb85c00ULL ), E820_TYPE_RSVD },
{ 0xe0000000ULL, ( 0xf0000000ULL - 0xe0000000ULL ), E820_TYPE_RSVD },
{ 0xfe000000ULL, (0x100000000ULL - 0xfe000000ULL ), E820_TYPE_RSVD },
{0x100000000ULL, (0x230000000ULL -0x100000000ULL ), E820_TYPE_RAM },
};
#define e820map __use_text16 ( e820map )
void fake_e820 ( void ) {
__asm__ __volatile__ (
TEXT16_CODE ( "\nint15_fakee820:\n\t"
"pushfw\n\t"
"cmpl $0xe820, %%eax\n\t"
"jne 99f\n\t"
"cmpl $0x534d4150, %%edx\n\t"
"jne 99f\n\t"
"pushaw\n\t"
"movw %%sp, %%bp\n\t"
"andb $~0x01, 22(%%bp)\n\t" /* Clear return CF */
"leaw e820map(%%bx), %%si\n\t"
"cs rep movsb\n\t"
"popaw\n\t"
"movl %%edx, %%eax\n\t"
"addl $20, %%ebx\n\t"
"cmpl %0, %%ebx\n\t"
"jne 1f\n\t"
"xorl %%ebx,%%ebx\n\t"
"\n1:\n\t"
"popfw\n\t"
"iret\n\t"
"\n99:\n\t"
"popfw\n\t"
"ljmp *%%cs:real_int15_vector\n\t" )
: : "i" ( sizeof ( e820map ) ) );
hook_bios_interrupt ( 0x15, ( unsigned int ) int15_fakee820,
&real_int15_vector );
}
void unfake_e820 ( void ) {
unhook_bios_interrupt ( 0x15, ( unsigned int ) int15_fakee820,
&real_int15_vector );
}