diff options
Diffstat (limited to 'purgatory/arch/i386/entry16.S')
| -rw-r--r-- | purgatory/arch/i386/entry16.S | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/purgatory/arch/i386/entry16.S b/purgatory/arch/i386/entry16.S deleted file mode 100644 index c4a3dad..0000000 --- a/purgatory/arch/i386/entry16.S +++ /dev/null @@ -1,160 +0,0 @@ -/* - * kexec: Linux boots Linux - * - * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation (version 2 of the License). - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - -#undef i386 - .text - .globl entry16, entry16_regs - .arch i386 - .balign 16 -entry16: - .code32 - /* Compute where I am running at */ - movl $entry16, %ebx - - /* Fixup my real mode segment */ - movl %ebx, %eax - shrl $4, %eax - movw %ax, 2 + realptr - - /* Fixup the gdt */ - movl %ebx, %eax - shll $16, %eax - - movl %ebx, %ecx - shrl $16, %ecx - andl $0xff, %ecx - - movl %ebx, %edx - andl $0xff000000, %edx - orl %edx, %ecx - - orl %eax, 0x08 + gdt - orl %ecx, 0x0c + gdt - orl %eax, 0x10 + gdt - orl %ecx, 0x14 + gdt - - - /* Setup the classic BIOS interrupt table at 0x0 */ - lidt idtptr - - /* Provide us with 16bit segments that we can use */ - lgdt gdt - - /* Note we don't disable the a20 line, (this shouldn't be required) - * The code to do it is in kexec_test and it is a real pain. - * I will worry about that when I need it. - */ - - /* Load 16bit data segments, to ensure the segment limits are set */ - movl $0x10, %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %ss - movl %eax, %fs - movl %eax, %gs - - /* switch to 16bit mode */ - ljmp $0x08, $1f - entry16 -1: - .code16 - /* Disable Paging and protected mode */ - /* clear the PG & PE bits of CR0 */ - movl %cr0,%eax - andl $~((1 << 31)|(1<<0)),%eax - movl %eax,%cr0 - - /* make intersegment jmp to flush the processor pipeline - * and reload %cs:%eip (to clear upper 16 bits of %eip). - */ - ljmp *(realptr - entry16) -3: - /* we are in real mode now - * set up the real mode segment registers : %ds, $ss, %es - */ - /* Setup the data segment */ - movw %cs, %ax - movw %ax, %ds - - /* Load the registers */ - movl eax - entry16, %eax - movl ebx - entry16, %ebx - movl ecx - entry16, %ecx - movl edx - entry16, %edx - movl esi - entry16, %esi - movl edi - entry16, %esi - movl esp - entry16, %esp - movl ebp - entry16, %ebp - movw es - entry16, %es - movw ss - entry16, %ss - movw fs - entry16, %fs - movw gs - entry16, %gs - movw ds - entry16, %ds - - /* Jump to the kernel entrypoint */ - ljmp %cs:*(realdest - entry16) - - .balign 4 -entry16_regs: -eax: .long 0x00000000 -ebx: .long 0x00000000 -ecx: .long 0x00000000 -edx: .long 0x00000000 -esi: .long 0x00000000 -edi: .long 0x00000000 -esp: .long 0x00000000 -ebp: .long 0x00000000 -ds: .word 0x0000 -es: .word 0x0000 -ss: .word 0x0000 -fs: .word 0x0000 -gs: .word 0x0000 -realdest: -ip: .word 0x0000 -cs: .word 0x0000 -pad: .word 0x0000 - .size entry16_regs, . - entry16_regs - - .balign 16 -realptr: - .word 3b - entry16 - .word 0x0000 - - .data - .balign 16 - -idtptr: - /* 256 entry idt at 0 */ - .word 0x400 - 1 - .word 0, 0 - - .balign 16 -gdt: - /* 0x00 unusable segment so used as the gdt ptr */ - .word gdt_end - gdt - 1 - .long gdt - .word 0 - - /* 0x08 16 bit real mode code segment */ - .word 0xffff, 0x0000 - .byte 0x00, 0x9b, 0x00, 0x00 - - /* 0x10 16 bit real mode data segment */ - .word 0xffff, 0x0000 - .byte 0x00, 0x93, 0x00, 0x00 -gdt_end: |