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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | /* * Copyright (C) 2009 Thomas Chou <thomas@wytron.com.tw> * * Based on arch/nios2/kernel/head.S * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * */ /* * This code can be loaded anywhere, eg FLASH ROM as reset vector, * as long as output does not overlap it. */ #include <linux/linkage.h> #include <asm/cache.h> .text .set noat ENTRY(_start) wrctl status, r0 /* disable interrupt */ /* invalidate all instruction cache */ movia r1, NIOS2_ICACHE_SIZE movui r2, NIOS2_ICACHE_LINE_SIZE 1: initi r1 sub r1, r1, r2 bgt r1, r0, 1b /* invalidate all data cache */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: initd 0(r1) sub r1, r1, r2 bgt r1, r0, 1b nextpc r1 /* Find out where we are */ chkadr: movia r2, chkadr beq r1, r2, finish_move /* We are running in correct address, done */ /* move code, r1: src, r2: dest, r3: last dest */ addi r1, r1, (_start - chkadr) /* Source */ movia r2, _start /* Destination */ movia r3, __bss_start /* End of copy */ 1: ldw r8, 0(r1) /* load a word from [r1] */ stw r8, 0(r2) /* stort a word to dest [r2] */ addi r1, r1, 4 /* inc the src addr */ addi r2, r2, 4 /* inc the dest addr */ blt r2, r3, 1b /* flush the data cache after moving */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: flushd 0(r1) sub r1, r1, r2 bgt r1, r0, 1b movia r1, finish_move jmp r1 /* jmp to linked address */ finish_move: /* zero out the .bss segment (uninitialized common data) */ movia r2, __bss_start /* presume nothing is between */ movia r1, _end /* the .bss and _end. */ 1: stb r0, 0(r2) addi r2, r2, 1 bne r1, r2, 1b /* * set up the stack pointer, some where higher than _end. * The stack space must be greater than 32K for decompress. */ movia sp, 0x10000 add sp, sp, r1 /* save args passed from u-boot, maybe */ addi sp, sp, -16 stw r4, 0(sp) stw r5, 4(sp) stw r6, 8(sp) stw r7, 12(sp) /* decompress the kernel */ call decompress_kernel /* pass saved args to kernel */ ldw r4, 0(sp) ldw r5, 4(sp) ldw r6, 8(sp) ldw r7, 12(sp) /* flush all data cache after decompressing */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: flushd 0(r1) sub r1, r1, r2 bgt r1, r0, 1b /* flush all instruction cache */ movia r1, NIOS2_ICACHE_SIZE movui r2, NIOS2_ICACHE_LINE_SIZE 1: flushi r1 sub r1, r1, r2 bgt r1, r0, 1b flushp /* jump to start real kernel */ movia r1, (CONFIG_NIOS2_MEM_BASE | CONFIG_NIOS2_KERNEL_REGION_BASE) jmp r1 .balign 512 fake_headers_as_bzImage: .short 0 .ascii "HdrS" .short 0x0202 .short 0 .short 0 .byte 0x00, 0x10 .short 0 .byte 0 .byte 1 .byte 0x00, 0x80 .long 0 .long 0 |