test4.c

linux 的引导程序源码The Microsoft&reg Windows&reg Software Development Kit (SDK) provides the documentation

/* test4.c */
/*
 Copyright 2001-2002 John Coffman.
 All rights reserved.

 Licensed under the terms contained in the file 'COPYING' in the LILO
 source directory.

*/
#include <bios.h>
#include "../bdata.h"

#define DISK_VERSION "2.1.1"

#if __MSDOS__==0
#define putch bios_putc
#define getch bios_getc
#define printf cprintf
#define CR 13
#else
#include <stdio.h>
#define putch(c) fputc((c),stdout)
#define getch getchar
#define CR 10
#endif

#define CTRL_C 03
#define SPACER "\f\n"
#define SEQ 0x3C4

#ifndef EDD_SUBSET
#define EDD_SUBSET 4
#define EDD_LOCK 2
#define EDD_PACKET 1
#endif
#ifndef SECTOR_SIZE
#define SECTOR_SIZE 512
#endif

typedef unsigned char  byte;
typedef unsigned short word;
typedef unsigned long dword;

extern union REGS   __argr;
extern struct SREGS __argseg;

union REGS reg, oreg;
struct SREGS sreg;
int last_good_disk;
int video_1 = 0xF00;
int num_hd = BD_MAX_HARD;
int errno;
dword hma;	/* highest memory address */
struct {
  long	start, start_hi,
	length, length_hi,
	mtype;
    } mem_map;
#define E820_MAGIC 0x534D4150

struct gdt_entry {
	unsigned short limit;
	unsigned short base01;
	unsigned char  base2;
	unsigned char  dtype;	/* 0x93 for data */
	unsigned char  limit2;	/* limit in low nibble, granularity & 32-bit in high nibble */
	unsigned char  base3;
};

struct gdt_entry gdt[6];

static
int hicopy (unsigned long to, unsigned long from, int wcount)
{
    int status;
    unsigned char save;
    
    memset(gdt, 0, sizeof(gdt));
    gdt[2].limit = gdt[3].limit = 0xFFFF;
    gdt[2].dtype = gdt[3].dtype = 0x93;
    
    gdt[2].base01 = from;
    gdt[2].base2 = from>>16;
    gdt[2].base3 = from>>24;
    
    gdt[3].base01 = to;
    gdt[3].base2 = to>>16;
    save = gdt[3].base3 = to>>24;
    
    segread(&sreg);
    sreg.es = sreg.ds;
    reg.h.ah = 0x87;
    reg.x.cx = wcount;
    reg.x.si = gdt;
/***    gdt[3].base3 &= 0;   / crosstalk */
    int86x(0x15, &reg, &oreg, &sreg);
    
    status = oreg.h.ah;
    if (oreg.x.cflag) status |= 0x100;
    if (save!=gdt[3].base3) status |= 0x200;
    errno |= status;
    return status;
}

unsigned long linear(void *ptr)
{
    segread(&sreg);
    return ((unsigned long)sreg.ds<<4) + (unsigned int)ptr;
}

word hipeekw(long address)
{
    word temp;
    hicopy(linear(&temp), address, 1);
    return temp;
}

int hipokew(long address, word value)
{
    return hicopy(address, linear(&value), 1);
}

#if __MSDOS__==0
static
bios_putc0(int c)
{
    union REGS reg;
    if (c=='\f') {
    	reg.h.ah = 0x0F;
    	int86(0x10, &reg, &reg);
    	reg.h.ah = 0;
    	int86(0x10, &reg, &reg);
    } else {
    	reg.h.al = c;
    	reg.h.ah = 14;
    	reg.x.bx = 7;
    	int86(0x10, &reg, &reg);
    }
}

void bios_putc(char c)
{
static int col;
   
    switch(c) {
    case '\t':
	do bios_putc(' '); while(col&7);
	break;
    case '\n':  bios_putc0('\r');
	/* fall into CR */
    case '\f':
    case '\r':	col=0;
    default:
        bios_putc0(c);
    	if (c>=' ' && c<0177) col++;
    }
}
#endif

static
int a20(void)	/* Return 1 if a20 is enabled, 0 if disabled */
{
#asm
 push	ds
 push	es
 xor	ax,ax
 mov	es,ax
 dec	ax
 mov	ds,ax
 cli
 mov	al,[0x10]
 mov	ah,al
 seg es
 cmp	al,[0]
 jne	a20_8
 xor	al,#0x5A
 mov	[0x10],al
 seg es
 cmp	al,[0]
 jne	a20_8
 xor	al,al
 jmp	a20_9
a20_8:
 mov	al,#1
a20_9:
 mov	[0x10],ah
 cbw
 sti
 pop	es
 pop	ds
#endasm
}

static
void sizeit(unsigned long sectors)
{
static char suf[] = "KMGT";
    int fract;
    char *cp;

/* print disk size in K,M,G,T */
    sectors /= 2;
    cp = suf;
    if (sectors <= 999) {
	printf("%ld%c", sectors, *cp);
	return;
    }
    cp++;
    while (sectors > 999999) {
	sectors /= 1000;
	cp++;
    }
    if (sectors > 2999) {
	sectors *= 1024;
	sectors /= 1000;
    }
    sectors += 5;	/* round decimal part */
    sectors /= 10;
    fract = sectors % 100;
    sectors /= 100;
    printf("%ld.%02d%c", sectors, fract, *cp);
}

static
void banner(char *version)
{
	printf(	"\n\n\n"
">>>> Disk Detection and Parameter Display <<<<\n\n\n"
"Version %s, Copyright (C) 1999-2002  John Coffman <[e-mail]>\n"
"Portions Copyright (C) 1996-2001 Robert de Bath, used with permission\n"
"Re-use and redistribution rights set forth in the file \"COPYING\".\n\n",
	 version);
}

static
int smsw(void)
{
#asm
  smsw	ax
#endasm
}

static
long e820(long b)
{
#asm
  push	bp
  mov	bp,sp
  push	ds
  pop	es
  mov	di,#_mem_map
  mov	eax,#0xE820
  mov	ebx,[bp+4]
  mov	ecx,#20
  mov	edx,#E820_MAGIC
  stc
  int	0x15
  jc	e820_err
  cmp	eax,#E820_MAGIC
  mov	ax,#-2
  jne	e820_exit
  cmp	ecx,#20
  mov	ax,#-3
  jne	e820_exit
  push	ebx
  pop	ax
  pop	dx
  jmp	e820_exit
e820_err:
  mov	ax,#-1
e820_err2:
  cwd
e820_exit:
  leave
#endasm
}

static
int inb(int port)
{
#asm
  mov	bx,sp
  mov	dx,[bx+2]
  in	al,dx
  xor	ah,ah
#endasm
}

static
int outb(int port, int data)
{
#asm
  mov	bx,sp
  mov	dx,[bx+2]
  mov	ax,[bx+4]
  out	dx,al
#endasm
}

static
void v86test(void)
{
static char s1[] = "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n";

    if (smsw()&1) {
	printf(s1);
	printf( "!!! ***  Warning:  DOS is not running in REAL mode  *** !!!\n"
		"!!! ***     Reported results may not be accurate    *** !!!\n" );
	printf(s1);
    }
}

static
void yesno(int i)
{
    printf("%s\n", i?"yes":"no");
}

static
void decimal(unsigned long value)
{
    unsigned int v[4];
    int i;
    for (i=0; i<4; i++) {
    	v[i] = value % 1000;
    	value /= 1000;
    }
    if (v[3]) printf("%d,%03d,%03d,%03d", v[3], v[2], v[1], v[0]);
    else if (v[2]) printf("%d,%03d,%03d", v[2], v[1], v[0]);
    else if (v[1]) printf("%d,%03d", v[1], v[0]);
    else printf("%d", v[0]);
}

static
void print_regs(union REGS *reg) {
    printf("AX=%04x  BX=%04x  CX=%04x  DX=%04x  SI=%04x  DI=%04x\n",
    reg->x.ax, reg->x.bx, reg->x.cx, reg->x.dx, reg->x.si, reg->x.di);
}

static 
void print_sregs(struct SREGS *sreg) {
    printf("DS=%04x  ES=%04x  CS=%04x  SS=%04x\n",
    		sreg->ds, sreg->es, sreg->cs, sreg->ss);
}

static
int is_msdos(void)
{
#if __MSDOS__
    return 1;
#else
    return (__argseg.es+0x10 == __argseg.cs);
#endif
}

static
void pause(void)
{
	char ch;
/* Must be standalone */    
	printf("\n\n\nHit <Enter> to continue, <^C> to quit ...");
	do {
	    ch = getch();
	    if (ch==CTRL_C) exit(0);
#if DEBUG>=1
	    if (ch != CR) printf(" %o", ch);
#endif
	} while (ch != CR);
	printf("\n");
}

static
void video_fix(void)
{
   outb(SEQ, 1);
   video_1 = inb(SEQ+1);
/* dirty hack for DELL Dimension 4300 computers */
   printf("\f\n");
}

static void print_carry(int flag)
{
    printf("    Carry = %d\n", flag);
}

static
void get_equip_cfg(void)
{
static char *vmode[4] = { "reserved", "40x25 color",
		"80x25 color", "80x25 monochrome" };
    word flag;
    int n;
    
    pause();
    printf(SPACER
    		"Int 11h\t\t\t\t[PC][AT][PS/2]\n"
    		"Get Equipment Configuration\n\n"
    		"Returns:\n    ");
    flag = int86(0x11, &reg, &reg);
    print_regs(&reg);
    
    printf("\nHas floppy drive(s): "); yesno(flag&1);
    printf("Has math coprocessor: "); yesno(flag&2);
    printf("Has pointing device: "); yesno(flag&4);
    printf("Initial video mode: %s\n", vmode[(flag>>4)&3]);
    n = flag&1 ? ((flag>>6)&3)+1 : 0;
    if (n) printf("Floppy drives installed: %d\n", ((flag>>6)&3)+1 );
    n = (flag>>9)&7;
    printf("Serial interfaces: %d\n", n);
    printf("Has game adapter: "); yesno(flag&4096);
    n = (flag>>14)&3;
    printf("Parallel interfaces: %d\n", n);
}

static
void get_conv_mem(void)
{
    int mem;
    
    pause();
    printf(SPACER
    		"Int 12h\t\t\t\t[PC][AT][PS/2]\n"
    		"Get Conventional Memory Size\n\n"
    		"Returns:\n    ");
    mem = int86(0x12, &reg, &reg);
    print_regs(&reg);
    printf("\nThere is %dK of low memory.    EBDA size = %dK   EBDA starts at 0x%lx\n",
    	mem, 640-mem, (long)mem<<10 );
    printf("\n(The A20 line is %sabled.)\n", a20() ? "en" : "dis");
}

static
void mov_ext_mem(void)
{
    word status, temp, vtemp;
    dword high, veryhigh;
        
    pause();
    segread(&sreg);
    sreg.es = sreg.ds;
    printf(SPACER
    		"Int 15h  Function 87h\t\t[AT][PS/2]\n"
    		"Move Extended Memory Block\n\n"
    		"Call With:\n    ");
    		print_sregs(&sreg);
    		reg.x.ax = 0x8700;
    		reg.x.cx = 1;
    		reg.x.si = &gdt;
    		printf("    ");
    		print_regs(&reg);
    		
    	high = 1024L*(1024L+128)-2;	/* 1Mb + 128K */
    	veryhigh = high+16L*1024L*1024L;
    	if (veryhigh >= hma) veryhigh=0;
#define WORDA 0xA5C6
#define WORDB 0x6CA5

	errno = 0;
	temp = hipeekw(high);
	status = hipokew(high, WORDA^temp);
    	printf("\nReturns:\n    ");
    	print_sregs(&sreg);
    	printf("    ");
    	print_regs(&oreg);
    	print_carry((status>>8) & 1);

	printf("\nR/W test at address %08lx ", high);
	if (hipeekw(high) != (WORDA^temp)) errno |= 0x400;
	hipokew(high, temp);
	if (hipeekw(high) != temp) errno |= 0x800;
	printf("%ssuccessful\n", errno ? "un" : "");
	if (errno) printf("Error code = 0x%04x\n", errno);
	
	if (veryhigh) {
		printf("R/W test at address %08lx ", veryhigh);
		vtemp = hipeekw(veryhigh);
		hipokew(veryhigh, WORDB^vtemp);
		if (hipeekw(high) != temp) errno |= 0x200;
		if (hipeekw(veryhigh) != (WORDB^vtemp)) errno |= 0x400;
		hipokew(veryhigh, vtemp);
		if (hipeekw(high) != temp) errno |= 0x200;
		if (hipeekw(veryhigh) != vtemp) errno |= 0x800;
		printf("%ssuccessful\n", errno ? "un" : "");
		if (errno) printf("Error code = 0x%04x\n", errno);
	}
    	if (errno & 0xE00)
    	    printf("\nThere is crosstalk between the two addresses\n"
    	    	"The function does not support full 386 32-bit addressing.\n");
}

#define NAREA 32

static
void get_ext_mem(void)
{
    long b, b1;
    dword t;
    int i;
    
    pause();
    printf(SPACER
    		"Int 15h  Function E820h\t\t[EXT]\n"
    		"Get Memory Map\n\n"
    		"Call With:\n"
    		"    EAX=0000E820  EBX=00000000  ECX=00000014  EDX=%lx\n\n",
    		E820_MAGIC );

    b = e820(b1=i=0);
    if (b > 0) {
	dword start[NAREA], length[NAREA];
	int j, k, ovlap;

    /*           00    000000000000   000000000000   (1) avail	*/
	printf("EBX        Start         Length      Type\n\n");
	do {
	    printf(" %02lx    %04hx%08lx   %04hx%08lx   (%d) %s\n", b1,
		(short)mem_map.start_hi, mem_map.start,
		(short)mem_map.length_hi, mem_map.length, (int)mem_map.mtype,
		mem_map.mtype == 1 ? "available" :
		mem_map.mtype == 2 ? "reserved"  :
		mem_map.mtype == 3 ? "ACPI" :
		mem_map.mtype == 4 ? "NVS"  :  "unknown-reserved");
	    if (mem_map.mtype==1 && mem_map.start_hi==0 && mem_map.start<=1024L*1024L) {
		if (mem_map.length_hi==0) hma = mem_map.start+mem_map.length;
		else hma = 0xFFF00000L;
	    }
	    if (i < NAREA) {
		start[i] = *(dword*)(((char*)&mem_map.start)+1);
		length[i] = *(dword*)(((char*)&mem_map.length)+1);
	    }
	    i++;
	    b = e820(b1=b);
	} while (b1 > 0);
	printf("\n");
	if (i > NAREA) {
	    i = NAREA;
	}
	ovlap = 0;
	for (k=0; k<i-1; k++) {