vgaemu.c

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

/*	$Id: vgaemu.c,v 1.2 2003/05/21 10:17:24 pefo Exp $ */

/*
 * Copyright (c) 2002 Opsycon AB  (www.opsycon.se)
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Opsycon AB.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
#include "biosemui.h"
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <termio.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <pmon.h>

void vga_bios_init (void);
void vga_putc(char c);
void vga_puts(char *s);
void vga_setmode(char mode);
void vga_doint10(int ax, int bx);

BE_sysEnv _BE_env;

static X86EMU_memFuncs _BE_mem = {
	BE_rdb,
	BE_rdw,
	BE_rdl,
	BE_wrb,
	BE_wrw,
	BE_wrl,
};

static X86EMU_pioFuncs _BE_pio = {
	BE_inb,
	BE_inw,
	BE_inl,
	BE_outb,
	BE_outw,
	BE_outl,
};

static int vga_done = 0;

#define OFF(addr)	(((addr) >> 0) & 0xffff)
#define SEG(addr)	(((addr) >> 4) & 0xf000)

#define MEM_SIZE	(64*1024)		/* should be plenty for now */


static void
vga_sys_init (void *rom_addr, u32 rom_size, void *busmem_addr, u32 busmem_size)
{
	extern int memorysize;

	memset(&M, 0, sizeof(M));

	/* grab some memory from the top of memory */
	memorysize = (memorysize - (5*MEM_SIZE)) & ~3;

	/* Setup the RAM buffer access */
	M.mem_base = (memorysize & 0x3fffffff) + (CLIENTPC & 0xc0000000);
	M.mem_size = MEM_SIZE;
	memset((void *)M.mem_base, 0, MEM_SIZE);

	/* Shadow the VGA ROM to memory */
	_BE_env.biosmem_base = M.mem_base + MEM_SIZE;
	memcpy((void *)_BE_env.biosmem_base, rom_addr, rom_size);
	_BE_env.biosmem_limit = _BE_env.biosmem_base + 4*MEM_SIZE - 1;

	/* Fill all entrys with hlt (note area starts at 0xc0000) */
	memset((char *)_BE_env.biosmem_base + 0x30000, 0xf4, 0x10000);
	/* set bios date */
	strcpy((char *)_BE_env.biosmem_base + 0x3fff5, "06/01/99");
	/* set up eisa ident string */
	strcpy((char *)_BE_env.biosmem_base + 0x3ffd9, "PCI/ISA");
	/* write system model id for IBM-AT */
	*((char *)_BE_env.biosmem_base + 0x3fffe) = 0xfc;

	/* Setup the video memory access */
	_BE_env.busmem_base = (u32) busmem_addr;
	_BE_env.busmem_limit = _BE_env.busmem_base + busmem_size - 1;

	/* Initialize the System BIOS */
	_BE_bios_init();
	X86EMU_setupMemFuncs(&_BE_mem);
	X86EMU_setupPioFuncs(&_BE_pio);
}

void
vga_bios_init()
{
extern pcitag_t have_vga;

  pcireg_t rom_addr;
  pcireg_t rom_size;
  void *busmem_addr = (void *)0xc00a0000;
  int busmem_size = 0x20000;
  int bus = (have_vga >> 16) & 0xff;
  int dev_fn = (have_vga >> 8) & 0xff;

	if (vga_done || have_vga == 0) {
		return;
	}

	rom_addr = _pci_conf_read(have_vga, PCI_MAPREG_ROM);
	_pci_conf_write(have_vga, PCI_MAPREG_ROM, PCI_MAPREG_MEM_ADDR_MASK);
	rom_size = -_pci_conf_read(have_vga, PCI_MAPREG_ROM);
	_pci_conf_write(have_vga, PCI_MAPREG_ROM, rom_addr);
	rom_addr &= PCI_MAPREG_MEM_ADDR_MASK;

	rom_addr += 0xc0000000;

	vga_sys_init((void *)rom_addr, rom_size, busmem_addr, busmem_size);

	if (BE_rdw(0xc0000) != 0xaa55) {
		printf("vga: No VGA BIOS ROM found!\n");
		return;
	}

	/* Setup the emulator to run the VGA BIOS */
	M.x86.R_CS = SEG(0xc0003);
	M.x86.R_IP = OFF(0xc0003);

	/* Set the PCI bus, device and function numbers */
	M.x86.R_AL = dev_fn;
	M.x86.R_AH = bus;

	/* Setup the emulator exit */
	BE_wrb(0x8000, 0xf4);	/* HALT opcode */

	/* Setup the stack to point to the emulator exit */
	M.x86.R_SS = SEG(M.mem_size - 4);
	M.x86.R_SP = OFF(M.mem_size - 4);
	BE_wrw(0xfffc, 0x8000);	/* IP */
	BE_wrw(0xfffe, 0x0000);	/* CS */

	X86EMU_exec();

	vga_done = 1;

	return;
}

static int
vga_bios_call (X86EMU_regs *inregs, X86EMU_regs *outregs)
{
	if (!vga_done) {
		return 0;
	}

	/* Setup the stack */
	M.x86.R_SS = SEG(M.mem_size - 4);
	M.x86.R_SP = OFF(M.mem_size - 4);

	/* Set the entry registers */
	M.x86.R_AX = inregs->R_AX;
	M.x86.R_BX = inregs->R_BX;
	M.x86.R_CX = inregs->R_CX;
	M.x86.R_DX = inregs->R_DX;
	M.x86.R_SI = inregs->R_SI;
	M.x86.R_DI = inregs->R_DI;
	M.x86.R_DS = inregs->R_DS;
	M.x86.R_ES = inregs->R_ES;
	M.x86.R_FLG = inregs->R_FLG;

	/* Setup to run the VGA BIOS interrupt call */
	M.x86.R_CS = SEG(0x8000);
	M.x86.R_IP = OFF(0x8000);
	BE_wrb(0x8000, 0xcd);	/* INT 10 */
	BE_wrb(0x8001, 0x10);

	/* Setup the emulator exit */
	BE_wrb(0x8002, 0xf4);	/* HALT opcode */

	/* Run the emulator */
	X86EMU_exec();

	/* Set the return registers */
	outregs->R_AX = M.x86.R_AX;
	outregs->R_BX = M.x86.R_BX;
	outregs->R_CX = M.x86.R_CX;
	outregs->R_DX = M.x86.R_DX;
	outregs->R_SI = M.x86.R_SI;
	outregs->R_DI = M.x86.R_DI;
	outregs->R_DS = M.x86.R_DS;
	outregs->R_ES = M.x86.R_ES;
	outregs->R_FLG = M.x86.R_FLG;

	return 1;
}

void vga_putc(char c)
{
	X86EMU_regs regs;

	if (!vga_done || c == 7) {
		return;
	}

	regs.R_AH = 0x0E;	/* Function number */
	regs.R_AL = c;		/* ASCII code */
	regs.R_BH = 0;		/* Page number */
	regs.R_BL = 15;		/* Color (graphics mode only */
	vga_bios_call(&regs, &regs);
}

void vga_puts(char *s)
{
	if (!vga_done) {
		return;
	}

	while (*s != '\0')
		vga_putc(*s++);
	vga_putc('\r');
	vga_putc('\n');
}

void vga_setmode(char mode)
{
	X86EMU_regs regs;

	regs.R_AH = 0x0;	/* Function number */
	regs.R_AL = mode;	/* Video Mode */
	vga_bios_call(&regs, &regs);
}

void vga_doint10(int ax, int bx)
{
	X86EMU_regs regs;

	regs.R_AX = ax;
	regs.R_BX = bx;
	vga_bios_call(&regs, &regs);
}