| /* ----------------------------------------------------------------------- |
| * |
| * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved |
| * Copyright 2009 Intel Corporation; author: H. Peter Anvin |
| * |
| * 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, Inc., 51 Franklin St, Fifth Floor, |
| * Boston MA 02110-1301, USA; either version 2 of the License, or |
| * (at your option) any later version; incorporated herein by reference. |
| * |
| * ----------------------------------------------------------------------- */ |
| |
| /* |
| * Simple stub to get us to the right point in the 32-bit code; |
| * this module must be linked first |
| */ |
| |
| .section ".init", "ax" |
| .globl _start |
| _start: |
| /* Zero the bss */ |
| cld |
| movl $__bss_start, %edi |
| movl $__bss_end, %ecx |
| subl %edi, %ecx |
| xorl %eax, %eax |
| shrl $2, %ecx |
| rep ; stosl |
| |
| /* Set up the protected-mode IDT and the interrupt jump buffers */ |
| movl $idt, %edi |
| movl $ijb, %eax |
| movl $0xee000000, %ebx /* Interrupt gate */ |
| movw %cs, %bx /* Target segment */ |
| |
| /* Make the IDT */ |
| movl $256, %ecx |
| 1: |
| stosl |
| stosl |
| movl %ebx, -6(%edi) |
| addl $8, %eax |
| loop 1b |
| |
| /* |
| * Each entry in the interrupt jump buffer contains the following |
| * instructions: |
| * |
| * 60 pushal |
| * b0xx movb $xx, %al # interrupt number |
| * e9xxxxxxxx jmp handle_interrupt |
| */ |
| movl $0xe900b060, %eax |
| movl $256, %ecx |
| 1: |
| movl %eax, (%edi) |
| addl $(1 << 16), %eax |
| movl $handle_interrupt-8, %edx |
| subl %edi, %edx |
| movl %edx, 4(%edi) |
| addl $8, %edi |
| loop 1b |
| |
| #if __SIZEOF_POINTER__ == 4 |
| lidtl idt_ptr |
| #elif __SIZEOF_POINTER__ == 8 |
| lidt idt_ptr |
| #else |
| #error "unsupported architecture" |
| #endif |
| |
| /* Save arguments, switch stacks */ |
| movl %esp, %eax /* Pointer to arguments */ |
| movl $__stack_end, %esp |
| |
| call setup |
| jmp *(rm_args) /* First argument is return */ |
| |
| .section ".text","ax" |
| .globl intcall |
| .type intcall, @function |
| intcall: |
| jmp *(rm_args+1*4) /* Intcall is argument 1 */ |
| .size intcall, .-intcall |
| |
| .type handle_interrupt, @function |
| handle_interrupt: |
| jmp *(rm_args+4*4) /* Interrupt pointer is argument 4 */ |
| .size handle_interrupt, .-handle_interrupt |
| |
| .section ".rodata","a" |
| idt_ptr: |
| .word 8*256-1 |
| .long idt |
| .word 0 |
| |
| .section ".bss.large","aw" |
| .balign 2048 |
| idt: |
| .space 8*256 |
| ijb: |
| .space 8*256 |
| |
| __stack: |
| .space 65536 |
| __stack_end: |
