| 1 | /* boot.S - bootstrap the kernel */ |
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| 2 | /* Copyright (C) 1999 Free Software Foundation, Inc. |
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| 3 | |
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| 4 | This program is free software; you can redistribute it and/or modify |
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| 5 | it under the terms of the GNU General Public License as published by |
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| 6 | the Free Software Foundation; either version 2 of the License, or |
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| 7 | (at your option) any later version. |
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| 8 | |
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| 9 | This program is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | GNU General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU General Public License |
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| 15 | along with this program; if not, write to the Free Software |
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| 16 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
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| 17 | |
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| 18 | #define ASM 1 |
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| 19 | #include <multiboot.h> |
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| 20 | |
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| 21 | .text |
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| 22 | |
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| 23 | .code32 |
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| 24 | .globl start, _start |
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| 25 | |
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| 26 | /* This entry is not used actually. */ |
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| 27 | start: |
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| 28 | _start: |
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| 29 | jmp multiboot_entry |
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| 30 | |
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| 31 | /* Align 32 bits boundary. */ |
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| 32 | .align 4 |
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| 33 | |
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| 34 | /* Multiboot header. */ |
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| 35 | multiboot_header: |
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| 36 | /* magic */ |
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| 37 | .long MULTIBOOT_HEADER_MAGIC |
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| 38 | /* flags */ |
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| 39 | .long MULTIBOOT_HEADER_FLAGS |
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| 40 | /* checksum */ |
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| 41 | .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) |
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| 42 | /* header_addr */ |
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| 43 | .long multiboot_header |
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| 44 | /* load_addr */ |
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| 45 | .long _start |
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| 46 | /* load_end_addr */ |
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| 47 | .long _edata |
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| 48 | /* bss_end_addr */ |
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| 49 | .long _end |
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| 50 | /* entry_addr */ |
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| 51 | .long multiboot_entry |
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| 52 | |
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| 53 | multiboot_entry: |
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| 54 | /* Initialize the stack pointer. */ |
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| 55 | movl $(stack + STACK_SIZE), %esp |
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| 56 | |
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| 57 | /* Reset EFLAGS. */ |
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| 58 | pushl $0 |
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| 59 | popf |
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| 60 | |
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| 61 | /* Push the pointer to the Multiboot information structure. */ |
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| 62 | pushl %ebx |
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| 63 | /* Push the magic value. */ |
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| 64 | pushl %eax |
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| 65 | |
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| 66 | /* Now enter the C main function... */ |
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| 67 | call EXT_C(cmain) |
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| 68 | |
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| 69 | loop: hlt |
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| 70 | jmp loop |
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| 71 | |
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| 72 | /* Our stack area. */ |
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| 73 | .comm stack, STACK_SIZE |
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