diff options
Diffstat (limited to 'sys/i386/boot/netboot/start2.S')
| -rw-r--r-- | sys/i386/boot/netboot/start2.S | 447 |
1 files changed, 0 insertions, 447 deletions
diff --git a/sys/i386/boot/netboot/start2.S b/sys/i386/boot/netboot/start2.S deleted file mode 100644 index f59516e273f2..000000000000 --- a/sys/i386/boot/netboot/start2.S +++ /dev/null @@ -1,447 +0,0 @@ - -#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 - .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 -#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 - 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 -#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 - -/************************************************************************** -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 - - -/* - * 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 -**************************************************************************/ - -/* - * - * 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 $0x8, %ah /* ask for disk info */ - - sti - int $0x13 - cli - - jnc ok - /* - * Urk. Call failed. It is not supported for floppies by old BIOS's. - * Guess it's a 15-sector floppy. - */ - 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 $15, %cl /* max sector */ - movb $1, %dh /* max head */ - movb $1, %dl /* # floppy drives installed */ - /* es:di = parameter table */ - /* carry = 0 */ -ok: - - opsize - call _real_to_prot /* back to protected mode */ - - /* - * form a longword representing all this gunk: - * 6 bit zero - * 10 bit max cylinder (0 based) - * 8 bit max head (0 based) - * 2 bit zero - * 6 bit max sector (1 based) = # sectors - */ - movb %cl, %al /* Upper two bits of cylinder count */ - andl $192,%eax - leal 0(,%eax,4),%eax /* << 2 */ - movb %ch, %al /* Lower 8 bits */ - sall $16,%eax /* << 16 */ - movb %dh, %ah /* max head */ - andb $0x3f, %cl /* mask of cylinder gunk */ - movb %cl, %al /* max sector (and # sectors) */ - - pop %edi - pop %esi - pop %ebx - pop %ebp - ret - -/************************************************************************** -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 */ |