x86/include/kvm/bios.h

#ifndef BIOS_H_
#define BIOS_H_

/*
 * X86-32 Memory Map (typical)
 *					start      end
 * Real Mode Interrupt Vector Table	0x00000000 0x000003FF
 * BDA area				0x00000400 0x000004FF
 * Conventional Low Memory		0x00000500 0x0009FBFF
 * EBDA area				0x0009FC00 0x0009FFFF
 * VIDEO RAM				0x000A0000 0x000BFFFF
 * VIDEO ROM (BIOS)			0x000C0000 0x000C7FFF
 * ROMs & unus. space (mapped hw & misc)0x000C8000 0x000EFFFF 160 KiB (typically)
 * Motherboard BIOS			0x000F0000 0x000FFFFF
 * Extended Memory			0x00100000 0xFEBFFFFF
 * Reserved (configs, ACPI, PnP, etc)	0xFEC00000 0xFFFFFFFF
 */

#define REAL_MODE_IVT_BEGIN		0x00000000
#define REAL_MODE_IVT_END		0x000003ff

#define BDA_START			0x00000400
#define BDA_END				0x000004ff

#define EBDA_START			0x0009fc00
#define EBDA_END			0x0009ffff

#define E820_MAP_START			EBDA_START

#define MB_BIOS_BEGIN			0x000f0000
#define MB_FIRMWARE_BIOS_BEGIN		0x000e0000
#define MB_BIOS_END			0x000fffff

#define MB_BIOS_SIZE			(MB_BIOS_END - MB_BIOS_BEGIN + 1)
#define MB_FIRMWARE_BIOS_SIZE		(MB_BIOS_END - MB_FIRMWARE_BIOS_BEGIN + 1)

#define VGA_RAM_BEGIN			0x000a0000
#define VGA_RAM_END			0x000bffff

#define VGA_ROM_BEGIN			0x000c0000
#define VGA_ROM_OEM_STRING		VGA_ROM_BEGIN
#define VGA_ROM_OEM_STRING_SIZE		16
#define VGA_ROM_MODES			(VGA_ROM_OEM_STRING + VGA_ROM_OEM_STRING_SIZE)
#define VGA_ROM_MODES_SIZE		32
#define VGA_ROM_END			0x000c7fff

/* we handle one page only */
#define VGA_RAM_SEG			(VGA_RAM_BEGIN >> 4)
#define VGA_PAGE_SIZE			0x007d0 /* 80x25 */

/* real mode interrupt vector table */
#define REAL_INTR_BASE			REAL_MODE_IVT_BEGIN
#define REAL_INTR_VECTORS		256

/*
 * BIOS stack must be at absolute predefined memory address
 * We reserve 64 bytes for BIOS stack
 */
#define MB_BIOS_SS			0xfff7
#define MB_BIOS_SP			0x40

/*
 * When interfere with assembler code we need to be sure how
 * arguments are passed in real mode.
 */
#define bioscall __attribute__((regparm(3)))

#ifndef __ASSEMBLER__

#include <asm/bios/types.h>

struct biosregs {
	u32			eax;
	u32			ebx;
	u32			ecx;
	u32			edx;
	u32			esp;
	u32			ebp;
	u32			esi;
	u32			edi;
	u32			ds;
	u32			es;
	u32			fs;
	u32			eip;
	u32			eflags;
};

extern bioscall void int10_handler(struct biosregs *regs);
extern bioscall void int15_handler(struct biosregs *regs);

#endif

#endif /* BIOS_H_ */