| Pali Rohár | ed407be | 2012-10-29 07:54:01 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2011-2012 |
| 3 | * Pali Rohár <pali.rohar@gmail.com> |
| 4 | * |
| Wolfgang Denk | 1a45966 | 2013-07-08 09:37:19 +0200 | [diff] [blame] | 5 | * SPDX-License-Identifier: GPL-2.0+ |
| Pali Rohár | ed407be | 2012-10-29 07:54:01 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <config.h> |
| 9 | |
| 10 | relocaddr: /* address of this relocaddr section after coping */ |
| 11 | .word . /* address of section (calculated at compile time) */ |
| 12 | |
| 13 | startaddr: /* address of u-boot after copying */ |
| 14 | .word CONFIG_SYS_TEXT_BASE |
| 15 | |
| 16 | kernaddr: /* address of kernel after copying */ |
| 17 | .word KERNEL_ADDRESS |
| 18 | |
| 19 | kernsize: /* maximal size of kernel image */ |
| 20 | .word KERNEL_MAXSIZE |
| 21 | |
| 22 | kernoffs: /* offset of kernel image in loaded u-boot */ |
| 23 | .word KERNEL_OFFSET |
| 24 | |
| 25 | imagesize: /* maximal size of image */ |
| 26 | .word IMAGE_MAXSIZE |
| 27 | |
| 28 | ih_magic: /* IH_MAGIC in big endian from include/image.h */ |
| 29 | .word 0x56190527 |
| 30 | |
| 31 | /* |
| 32 | * Routine: save_boot_params (called after reset from start.S) |
| 33 | * Description: Copy attached kernel to address KERNEL_ADDRESS |
| 34 | * Copy u-boot to address CONFIG_SYS_TEXT_BASE |
| 35 | * Return to copied u-boot address |
| 36 | */ |
| 37 | |
| 38 | .global save_boot_params |
| 39 | save_boot_params: |
| 40 | |
| 41 | |
| 42 | /* Copy valid attached kernel to address KERNEL_ADDRESS */ |
| 43 | |
| 44 | copy_kernel_start: |
| 45 | adr r0, relocaddr /* r0 - address of section relocaddr */ |
| 46 | ldr r1, relocaddr /* r1 - address of relocaddr after relocation */ |
| 47 | cmp r0, r1 |
| 48 | |
| 49 | /* r4 - calculated offset */ |
| 50 | subhi r4, r0, r1 |
| 51 | sublo r4, r1, r0 |
| 52 | |
| 53 | /* r0 - start of kernel before */ |
| 54 | ldr r0, startaddr |
| 55 | addhi r0, r0, r4 |
| 56 | sublo r0, r0, r4 |
| 57 | ldr r1, kernoffs |
| 58 | add r0, r0, r1 |
| 59 | |
| 60 | /* r3 - start of kernel after */ |
| 61 | ldr r3, kernaddr |
| 62 | |
| 63 | /* r2 - end of kernel after */ |
| 64 | ldr r1, kernsize |
| 65 | add r2, r3, r1 |
| 66 | |
| 67 | /* r1 - end of kernel before */ |
| 68 | add r1, r0, r1 |
| 69 | |
| 70 | /* remove header in target kernel */ |
| 71 | mov r5, #0 |
| 72 | str r5, [r3] |
| 73 | |
| 74 | /* check for valid kernel uImage */ |
| 75 | ldr r4, [r0] /* r4 - 4 bytes header of kernel */ |
| 76 | ldr r5, ih_magic /* r5 - IH_MAGIC */ |
| 77 | cmp r4, r5 |
| 78 | bne copy_kernel_end /* skip if invalid image */ |
| 79 | |
| 80 | copy_kernel_loop: |
| 81 | ldmdb r1!, {r3 - r10} |
| 82 | stmdb r2!, {r3 - r10} |
| 83 | cmp r1, r0 |
| 84 | bhi copy_kernel_loop |
| 85 | |
| 86 | copy_kernel_end: |
| 87 | mov r5, #0 |
| 88 | str r5, [r0] /* remove 4 bytes header of kernel */ |
| 89 | |
| 90 | |
| 91 | /* Fix u-boot code */ |
| 92 | |
| 93 | fix_start: |
| 94 | adr r0, relocaddr /* r0 - address of section relocaddr */ |
| 95 | ldr r1, relocaddr /* r1 - address of relocaddr after relocation */ |
| 96 | cmp r0, r1 |
| 97 | |
| 98 | beq copy_uboot_end /* skip if u-boot is on correct address */ |
| 99 | |
| 100 | /* r5 - calculated offset */ |
| 101 | subhi r5, r0, r1 |
| 102 | sublo r5, r1, r0 |
| 103 | |
| 104 | /* r6 - maximal u-boot size */ |
| 105 | ldr r6, imagesize |
| 106 | |
| 107 | /* fix return address */ |
| 108 | subhi lr, lr, r5 |
| 109 | addlo lr, lr, r5 |
| 110 | |
| 111 | /* r1 - start of u-boot after */ |
| 112 | ldr r1, startaddr |
| 113 | |
| 114 | /* r0 - start of u-boot before */ |
| 115 | addhi r0, r1, r5 |
| 116 | sublo r0, r1, r5 |
| 117 | |
| 118 | /* check if we need to move uboot copy code before calling it */ |
| 119 | cmp r5, r6 |
| 120 | bhi copy_uboot_start /* now coping u-boot code directly is safe */ |
| 121 | |
| 122 | |
| 123 | copy_code_start: |
| 124 | /* r0 - start of u-boot before */ |
| 125 | /* r1 - start of u-boot after */ |
| 126 | /* r6 - maximal u-boot size */ |
| 127 | |
| 128 | /* r7 - maximal kernel size */ |
| 129 | ldr r7, kernsize |
| 130 | |
| 131 | /* r4 - end of kernel before */ |
| 132 | add r4, r0, r6 |
| 133 | add r4, r4, r7 |
| 134 | |
| 135 | /* r5 - end of u-boot after */ |
| 136 | ldr r5, startaddr |
| 137 | add r5, r5, r6 |
| 138 | |
| 139 | /* r2 - start of loop code after */ |
| 140 | cmp r4, r5 /* higher address (r4 or r5) */ |
| 141 | movhs r2, r4 |
| 142 | movlo r2, r5 |
| 143 | |
| 144 | /* r3 - end of loop code before */ |
| 145 | adr r3, end |
| 146 | |
| 147 | /* r4 - end of loop code after */ |
| 148 | adr r4, copy_uboot_start |
| 149 | sub r4, r3, r4 |
| 150 | add r4, r2, r4 |
| 151 | |
| 152 | copy_code_loop: |
| 153 | ldmdb r3!, {r7 - r10} |
| 154 | stmdb r4!, {r7 - r10} |
| 155 | cmp r4, r2 |
| 156 | bhi copy_code_loop |
| 157 | |
| 158 | copy_code_end: |
| 159 | mov pc, r2 |
| 160 | |
| 161 | |
| 162 | /* Copy u-boot to address CONFIG_SYS_TEXT_BASE */ |
| 163 | |
| 164 | copy_uboot_start: |
| 165 | /* r0 - start of u-boot before */ |
| 166 | /* r1 - start of u-boot after */ |
| 167 | /* r6 - maximal u-boot size */ |
| 168 | |
| 169 | /* r2 - end of u-boot after */ |
| 170 | add r2, r1, r6 |
| 171 | |
| 172 | /* condition for copying from left to right */ |
| 173 | cmp r0, r1 |
| 174 | addlo r1, r0, r6 /* r1 - end of u-boot before */ |
| 175 | blo copy_uboot_loop_right |
| 176 | |
| 177 | copy_uboot_loop_left: |
| 178 | ldmia r0!, {r3 - r10} |
| 179 | stmia r1!, {r3 - r10} |
| 180 | cmp r1, r2 |
| 181 | blo copy_uboot_loop_left |
| 182 | b copy_uboot_end |
| 183 | |
| 184 | copy_uboot_loop_right: |
| 185 | ldmdb r1!, {r3 - r10} |
| 186 | stmdb r2!, {r3 - r10} |
| 187 | cmp r1, r0 |
| 188 | bhi copy_uboot_loop_right |
| 189 | |
| 190 | copy_uboot_end: |
| 191 | bx lr |
| 192 | |
| 193 | end: |