freebsd-nq/sys/pc98/boot/netboot/start2.S
KATO Takenori 5904e1f57a Synchronize with foolowing files in sys/i386/boot/netboot:
1.12 Makefile
	1.14 bootmenu.c
	1.20 main.c
	1.3  makerom.c
	1.3  misc.c
	1.12 netboot.h
	1.11 ns8390.c
	1.1  ns8390.h
	1.3  rpc.c
	1.6  start2.S

Submitted by:	H. Nokubi <h-nokubi@nmit.mt.nec.co.jp>
1997-08-17 05:13:27 +00:00

723 lines
13 KiB
ArmAsm

#define STACKADDR 0xe000 /* Needs to be end of bss + stacksize */
#define KERN_CODE_SEG 0x08
#define KERN_DATA_SEG 0x10
#define REAL_MODE_CSEG 0x18
#define REAL_MODE_DSEG 0x20
#define CR0_PE 1
#define opsize .byte 0x66
#define addrsize .byte 0x67
/* At entry, the processor is in 16 bit real mode and the code is being
* executed from an address it was not linked to. Code must be pic and
* 32 bit sensitive until things are fixed up.
*/
#ifdef BOOTROM
#ifndef PC98
.word 0xaa55 /* bios extension signature */
.byte (ROMSIZE>>9) /* no. of 512B blocks */
jmp 1f /* enter from bios here */
.byte 0 /* checksum */
#ifdef PCI
.ascii "FreeBSD boot ROM.." /* 18 bytes total */
.word 0x1a
/* PCI rom data structure format */
.ascii "PCIR" /* signature */
.word PCI_VENDOR /* vendor ID */
.word PCI_DEVICE /* device ID */
.word 0 /* vital product data */
.word 0x0018 /* PCI data structure */
.byte 0 /* PCI data struct. rev -- 0 */
.byte PCI_CLASS /* Class code */
.word (ROMSIZE>>9) /* no. of 512B blocks */
.byte 0,0 /* rev. level */
.byte 0 /* code type - 0 =x86 */
.byte 0x80 /* indicator of last block */
.word 0 /* reserved */
#endif
1: push %eax
push %ds
xor %eax,%eax
mov %ax,%ds
.byte 0xa1 /* MOV 0x304,%ax */
.word 0x304
.byte 0x3d /* CMP $0x4d52, %ax == 'MR' */
.word 0x4d52
jz 2f
.byte 0xa1 /* MOV 0x64, %ax */
.word 0x64
.byte 0xa3 /* MOV %ax, 0x300 */
.word 0x300
.byte 0xa1 /* MOV 0x66, %ax */
.word 0x66
.byte 0xa3 /* MOV %ax, 0x302 */
.word 0x302
.byte 0xb8 /* MOV $_start-RELOCADDR, %ax */
.word (_start-RELOC)
.byte 0xa3 /* MOV %ax, 0x64 */
.word 0x64
mov %cs,%ax
.byte 0xa3 /* MOV %ax, 0x66 */
.word 0x66
.byte 0xb8 /* MOV 'MR',%ax */
.word 0x4d52
.byte 0xa3 /* MOV %ax, 0x304 */
.word 0x304
2: pop %ds
pop %eax
lret
#else /* defined PC98 */
.byte 0xcb /* 00 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 03 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 06 retf */
.byte 0x00
.byte 0x00
.byte 0x55 /* 09 MAGIC */
.byte 0xaa
.byte 0x00
.byte 0xeb /* 0c jmp 1f */
.byte 0x22
.byte 0x00
.byte 0xcb /* 0f retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 12 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 15 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 18 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 1b retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 1e retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 21 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 24 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 27 retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 2a retf */
.byte 0x00
.byte 0x00
.byte 0xcb /* 2d retf */
.byte 0x00
.byte 0x00
1:
cli
pusha
opsize
mov $0x1fc0, %eax
mov %ax, %es
mov %esp, %eax
addrsize
.byte 0x26 /* es: */
mov %eax, (0x0000)
mov %ss, %ax
addrsize
.byte 0x26 /* es: */
mov %eax, (0x0004)
#endif
#endif
/**************************************************************************
START - Where all the fun begins....
**************************************************************************/
.globl _start
_start:
cli
cld
#ifdef BOOTROM /* relocate ourselves */
xor %esi, %esi /* zero for ROMs */
#else
.byte 0xbe /* MOV $0x100,%si -- 100h for .COM */
.word 0x100
#endif
xor %edi,%edi
.byte 0xb8 /* MOV $RELOCADDR>>4, %ax */
.word (RELOC>>4)
mov %ax, %es
.byte 0xb9 /* MOV $ROMSIZE, %cx */
.word ROMSIZE
cs
rep
movsb
opsize
ljmp $(RELOC>>4),$1f-RELOC /* Jmp to RELOC:1f */
1:
nop
#ifdef PC98
opsize
mov $0x0a00, %eax /* 80 x 25 mode */
int $0x18
movb $0x0c, %ah /* text on */
int $0x18
movb $0x16, %ah /* t-vram clear */
opsize
mov $0xe100, %edx
int $0x18
/* cursor home and on */
xor %edx, %edx
movb $0x13, %ah
int $0x18
movb $0x11, %ah
int $0x18
/* set up %ds */
xor %ax, %ax
mov %ax, %ds
opsize
mov $0xa000, %eax
mov %ax, %es
/* transfer PC-9801 system common area to 0xa1000 */
opsize
mov $0x0000, %esi
opsize
mov $0x1000, %edi
opsize
mov $0x0630, %ecx
cld
rep
movsb
/* transfer EPSON machine type to 0xa1200 */
push %ds
opsize
mov $0xfd00, %eax
mov %ax, %ds
addrsize
opsize
mov 0x804, %eax
opsize
and $0x00ffffff, %eax
addrsize
opsize
.byte 0x26
mov %eax, %es: (0x1624)
pop %ds
#endif
mov %cs,%ax
mov %ax,%ds
mov %ax,%es
mov %ax,%ss
.byte 0xb8 /* MOV $STACKADDR, %ax */
.word STACKADDR
mov %eax,%esp
opsize
call _real_to_prot
call _main
.globl _exit
_exit:
call _prot_to_real
#ifndef PC98
#ifdef BOOTROM
xor %eax,%eax
mov %ax,%ds
.byte 0xa1 /* MOV 0x302, %ax */
.word 0x302
push %eax
.byte 0xa1 /* MOV 0x300, %ax */
.word 0x300
push %eax
lret
#else
int $0x19
#endif
#else /* defined PC98 */
#ifdef BOOTROM
cli
movb $0x0e, %al /* CPU RESET */
outb %al, $0x37
xor %eax, %eax
mov %ax, %es
push %cs
push $2f
addrsize
.byte 0x26 /* es: */
mov %esp, (0x0404)
addrsize
.byte 0x26 /* es: */
movw %ss, (0x0406)
movb $0x00, %al
outb %al, $0xf0
1:
jmp 1b
2:
movb $0x0f, %al
outb %al, $0x37
opsize /* restore ss:sp */
mov $0x1fc0, %eax
mov %ax, %es
addrsize
.byte 0x26 /* es: */
mov (0x0000), %ebx
addrsize
.byte 0x26 /* es: */
mov (0x0004), %eax
mov %ax, %ss
mov %ebx, %esp
sti
popa
lret
#else
mov $0x8000, %ecx
movb $0x00, %al
1:
jmp 1b
outb %al, $0x5f
loop 1b
outb %al, $0xf0
1:
jmp 1b
#endif
#endif
#ifndef PC98
/**************************************************************************
CURRTICKS - Get Time
**************************************************************************/
.globl _currticks
_currticks:
push %ebp
mov %esp,%ebp
push %ebx
push %esi
push %edi
xor %edx,%edx
call _prot_to_real
xor %eax,%eax
int $0x1a
opsize
call _real_to_prot
xor %eax,%eax
shl $16,%ecx
mov %edx,%eax
or %ecx,%eax
pop %edi
pop %esi
pop %ebx
pop %ebp
ret
/**************************************************************************
PUTCHAR - Print a character
**************************************************************************/
.globl _putchar
_putchar:
push %ebp
mov %esp,%ebp
push %ebx
push %esi
push %edi
movb 8(%ebp),%cl
call _prot_to_real
opsize
mov $1,%ebx
movb $0x0e,%ah
movb %cl,%al
int $0x10
opsize
call _real_to_prot
pop %edi
pop %esi
pop %ebx
pop %ebp
ret
/**************************************************************************
GETCHAR - Get a character
**************************************************************************/
.globl _getchar
_getchar:
push %ebp
mov %esp,%ebp
push %ebx
push %esi
push %edi
call _prot_to_real
movb $0x0,%ah
int $0x16
movb %al,%bl
opsize
call _real_to_prot
xor %eax,%eax
movb %bl,%al
pop %edi
pop %esi
pop %ebx
pop %ebp
ret
/**************************************************************************
ISKEY - Check for keyboard interrupt
**************************************************************************/
.globl _iskey
_iskey:
push %ebp
mov %esp,%ebp
push %ebx
push %esi
push %edi
call _prot_to_real
xor %ebx,%ebx
movb $0x1,%ah
int $0x16
opsize
jz 1f
movb %al,%bl
1:
opsize
call _real_to_prot
xor %eax,%eax
movb %bl,%al
pop %edi
pop %esi
pop %ebx
pop %ebp
ret
#else /* defined PC98 */
/**************************************************************************
Get Date & Time
**************************************************************************/
.globl _bios98getdate
_bios98getdate:
push %ebp
mov %esp,%ebp
push %ebx
push %es
call _prot_to_real
opsize
mov $0x1ff0, %eax
mov %ax, %es
movb $0x00, %ah
opsize
mov $0x80, %ebx /* bios uses 1ff0:0080 */
int $0x1c
opsize
mov $0x82, %ebx
opsize
.byte 0x26 /* es: */
.byte 0x8b /* mov (%ebx), %ebx */
.byte 0x1f
opsize
call _real_to_prot
mov %ebx, %eax
pop %es
pop %ebx
pop %ebp
ret
/*
* getc()
* BIOS call "INT 18H Function 00H" to read character from keyboard
* Call with %ah = 0x0
* Return: %ah = keyboard scan code
* %al = ASCII character
*/
.globl _getchar
_getchar:
push %ebp
mov %esp, %ebp
push %ebx /* save %ebx */
call _prot_to_real
movb $0x0, %ah
int $0x18
movb %al, %bl /* real_to_prot uses %eax */
opsize
call _real_to_prot
xor %eax, %eax
movb %bl, %al
pop %ebx
pop %ebp
ret
/*
* ischar()
* if there is a character pending, return it; otherwise return 0
* BIOS call "INT 18H Function 01H" to check whether a character is pending
* Call with %ah = 0x1
* Return:
* If key waiting to be input:
* %ah = keyboard scan code
* %al = ASCII character
* %bh = 1
* else
* %bh = 0
*/
.globl _iskey
_iskey:
push %ebp
mov %esp, %ebp
push %ebx
call _prot_to_real /* enter real mode */
xor %ebx, %ebx
movb $0x1, %ah
int $0x18
andb %bh, %bh
opsize
jz nochar
movb %al, %bl
nochar:
opsize
call _real_to_prot
xor %eax, %eax
movb %bl, %al
pop %ebx
pop %ebp
ret
#endif
/*
* C library -- _setjmp, _longjmp
*
* longjmp(a,v)
* will generate a "return(v)" from the last call to
* setjmp(a)
* by restoring registers from the stack.
* The previous signal state is restored.
*/
.globl _setjmp
_setjmp:
movl 4(%esp),%ecx
movl 0(%esp),%edx
movl %edx, 0(%ecx)
movl %ebx, 4(%ecx)
movl %esp, 8(%ecx)
movl %ebp,12(%ecx)
movl %esi,16(%ecx)
movl %edi,20(%ecx)
movl %eax,24(%ecx)
movl $0,%eax
ret
.globl _longjmp
_longjmp:
movl 4(%esp),%edx
movl 8(%esp),%eax
movl 0(%edx),%ecx
movl 4(%edx),%ebx
movl 8(%edx),%esp
movl 12(%edx),%ebp
movl 16(%edx),%esi
movl 20(%edx),%edi
cmpl $0,%eax
jne 1f
movl $1,%eax
1: movl %ecx,0(%esp)
ret
/**************************************************************************
___MAIN - Dummy to keep GCC happy
**************************************************************************/
.globl ___main
___main:
ret
/**************************************************************************
REAL_TO_PROT - Go from REAL mode to Protected Mode
**************************************************************************/
.globl _real_to_prot
_real_to_prot:
cli
cs
addrsize
lgdt gdtarg-RELOC
mov %cr0, %eax
opsize
or $CR0_PE, %eax
mov %eax, %cr0 /* turn on protected mode */
/* jump to relocation, flush prefetch queue, and reload %cs */
opsize
ljmp $KERN_CODE_SEG, $1f
1:
/* reload other segment registers */
movl $KERN_DATA_SEG, %eax
movl %ax, %ds
movl %ax, %es
movl %ax, %ss
add $RELOC,%esp /* Fix up stack pointer */
pop %eax /* Fix up return Address */
add $RELOC,%eax
push %eax
ret
/**************************************************************************
PROT_TO_REAL - Go from Protected Mode to REAL Mode
**************************************************************************/
.globl _prot_to_real
_prot_to_real:
pop %eax
sub $RELOC,%eax /* Adjust return address */
push %eax
sub $RELOC,%esp /* Adjust stack pointer */
/* Prepare %ax while we're still in a mode that gas understands. */
movw $REAL_MODE_DSEG, %ax
ljmp $REAL_MODE_CSEG, $1f-RELOC /* jump to a 16 bit segment */
1:
mov %ax, %ds
mov %ax, %ss
mov %ax, %es
mov %ax, %fs
/* clear the PE bit of CR0 */
mov %cr0, %eax
opsize
andl $0!CR0_PE, %eax
mov %eax, %cr0
/* make intersegment jmp to flush the processor pipeline
* and reload CS register
*/
opsize
ljmp $(RELOC)>>4, $2f-RELOC
2:
/* we are in real mode now
* set up the real mode segment registers : DS, SS, ES
*/
mov %cs, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %ss
sti
opsize
ret
/**************************************************************************
GET DISK GEOMETRY INFO
**************************************************************************/
#ifdef PC98
/*
*
* get_diskinfo(): return a word that represents the
* max number of sectors and heads and drives for this device
*
*/
.globl _get_diskinfo
_get_diskinfo:
push %ebp
mov %esp, %ebp
push %ebx
push %esi
push %edi
movb 0x8(%ebp), %dl /* diskinfo(drive #) */
call _prot_to_real /* enter real mode */
movb %dl, %al /* ask for disk info */
andb $0xf0, %al
cmpb $0x90, %al
jz fdd
movb %dl, %al
movb $0x84, %ah
int $0x1b
jnc ok
/*
* Urk. Call failed. It is not supported for floppies by old BIOS's.
* Guess it's a 15-sector floppy.
*/
fdd:
subb %ah, %ah /* %ax = 0 */
movb %al, %al
movb %ah, %bh /* %bh = 0 */
movb $2, %bl /* %bl bits 0-3 = drive type,
bit 2 = 1.2M */
movb $79, %ch /* max track */
movb $1, %cl /* # floppy drives installed */
movb $2, %dh /* max head */
movb $15, %dl /* max sector */
/* es:di = parameter table */
/* carry = 0 */
ok:
opsize
call _real_to_prot /* back to protected mode */
/*
* form a longword representing all this gunk:
* 16 bit cylinder
* 8 bit head
* 8 bit sector
*/
mov %ecx, %eax
sall $16,%eax /* << 16 */
movb %dh, %ah /* max head */
movb %dl, %al /* max sector (and # sectors) */
pop %edi
pop %esi
pop %ebx
pop %ebp
ret
#endif
/**************************************************************************
GLOBAL DESCRIPTOR TABLE
**************************************************************************/
.align 4
gdt:
.word 0, 0
.byte 0, 0x00, 0x00, 0
/* code segment */
.word 0xffff, 0
.byte 0, 0x9f, 0xcf, 0
/* data segment */
.word 0xffff, 0
.byte 0, 0x93, 0xcf, 0
/* 16 bit real mode code segment */
.word 0xffff, RELOC & 0xffff
.byte (RELOC>>16), 0x9b, 0x00, (RELOC>>24)
/* 16 bit real mode data segment */
.word 0xffff, RELOC & 0xffff
.byte (RELOC>>16), 0x93, 0x00, (RELOC>>24)
.align 4
gdtarg:
.word 0x27 /* limit */
.long gdt /* addr */