Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * relocate_kernel.S - put the kernel image in place to boot |
| 3 | * 2005.9.17 kogiidena@eggplant.ddo.jp |
| 4 | * |
| 5 | * LANDISK/sh4 is supported. Maybe, SH archtecture works well. |
| 6 | * |
| 7 | * 2009-03-18 Magnus Damm - Added Kexec Jump support |
| 8 | * |
| 9 | * This source code is licensed under the GNU General Public License, |
| 10 | * Version 2. See the file COPYING for more details. |
| 11 | */ |
| 12 | #include <linux/linkage.h> |
| 13 | #include <asm/addrspace.h> |
| 14 | #include <asm/page.h> |
| 15 | |
| 16 | .globl relocate_new_kernel |
| 17 | relocate_new_kernel: |
| 18 | /* r4 = indirection_page */ |
| 19 | /* r5 = reboot_code_buffer */ |
| 20 | /* r6 = start_address */ |
| 21 | |
| 22 | mov.l 10f, r0 /* PAGE_SIZE */ |
| 23 | add r5, r0 /* setup new stack at end of control page */ |
| 24 | |
| 25 | /* save r15->r8 to new stack */ |
| 26 | mov.l r15, @-r0 |
| 27 | mov r0, r15 |
| 28 | mov.l r14, @-r15 |
| 29 | mov.l r13, @-r15 |
| 30 | mov.l r12, @-r15 |
| 31 | mov.l r11, @-r15 |
| 32 | mov.l r10, @-r15 |
| 33 | mov.l r9, @-r15 |
| 34 | mov.l r8, @-r15 |
| 35 | |
| 36 | /* save other random registers */ |
| 37 | sts.l macl, @-r15 |
| 38 | sts.l mach, @-r15 |
| 39 | stc.l gbr, @-r15 |
| 40 | stc.l ssr, @-r15 |
| 41 | stc.l sr, @-r15 |
| 42 | sts.l pr, @-r15 |
| 43 | stc.l spc, @-r15 |
| 44 | |
| 45 | /* switch to bank1 and save r7->r0 */ |
| 46 | mov.l 12f, r9 |
| 47 | stc sr, r8 |
| 48 | or r9, r8 |
| 49 | ldc r8, sr |
| 50 | mov.l r7, @-r15 |
| 51 | mov.l r6, @-r15 |
| 52 | mov.l r5, @-r15 |
| 53 | mov.l r4, @-r15 |
| 54 | mov.l r3, @-r15 |
| 55 | mov.l r2, @-r15 |
| 56 | mov.l r1, @-r15 |
| 57 | mov.l r0, @-r15 |
| 58 | |
| 59 | /* switch to bank0 and save r7->r0 */ |
| 60 | mov.l 12f, r9 |
| 61 | not r9, r9 |
| 62 | stc sr, r8 |
| 63 | and r9, r8 |
| 64 | ldc r8, sr |
| 65 | mov.l r7, @-r15 |
| 66 | mov.l r6, @-r15 |
| 67 | mov.l r5, @-r15 |
| 68 | mov.l r4, @-r15 |
| 69 | mov.l r3, @-r15 |
| 70 | mov.l r2, @-r15 |
| 71 | mov.l r1, @-r15 |
| 72 | mov.l r0, @-r15 |
| 73 | |
| 74 | mov.l r4, @-r15 /* save indirection page again */ |
| 75 | |
| 76 | bsr swap_pages /* swap pages before jumping to new kernel */ |
| 77 | nop |
| 78 | |
| 79 | mova 11f, r0 |
| 80 | mov.l r15, @r0 /* save pointer to stack */ |
| 81 | |
| 82 | jsr @r6 /* hand over control to new kernel */ |
| 83 | nop |
| 84 | |
| 85 | mov.l 11f, r15 /* get pointer to stack */ |
| 86 | mov.l @r15+, r4 /* restore r4 to get indirection page */ |
| 87 | |
| 88 | bsr swap_pages /* swap pages back to previous state */ |
| 89 | nop |
| 90 | |
| 91 | /* make sure bank0 is active and restore r0->r7 */ |
| 92 | mov.l 12f, r9 |
| 93 | not r9, r9 |
| 94 | stc sr, r8 |
| 95 | and r9, r8 |
| 96 | ldc r8, sr |
| 97 | mov.l @r15+, r0 |
| 98 | mov.l @r15+, r1 |
| 99 | mov.l @r15+, r2 |
| 100 | mov.l @r15+, r3 |
| 101 | mov.l @r15+, r4 |
| 102 | mov.l @r15+, r5 |
| 103 | mov.l @r15+, r6 |
| 104 | mov.l @r15+, r7 |
| 105 | |
| 106 | /* switch to bank1 and restore r0->r7 */ |
| 107 | mov.l 12f, r9 |
| 108 | stc sr, r8 |
| 109 | or r9, r8 |
| 110 | ldc r8, sr |
| 111 | mov.l @r15+, r0 |
| 112 | mov.l @r15+, r1 |
| 113 | mov.l @r15+, r2 |
| 114 | mov.l @r15+, r3 |
| 115 | mov.l @r15+, r4 |
| 116 | mov.l @r15+, r5 |
| 117 | mov.l @r15+, r6 |
| 118 | mov.l @r15+, r7 |
| 119 | |
| 120 | /* switch back to bank0 */ |
| 121 | mov.l 12f, r9 |
| 122 | not r9, r9 |
| 123 | stc sr, r8 |
| 124 | and r9, r8 |
| 125 | ldc r8, sr |
| 126 | |
| 127 | /* restore other random registers */ |
| 128 | ldc.l @r15+, spc |
| 129 | lds.l @r15+, pr |
| 130 | ldc.l @r15+, sr |
| 131 | ldc.l @r15+, ssr |
| 132 | ldc.l @r15+, gbr |
| 133 | lds.l @r15+, mach |
| 134 | lds.l @r15+, macl |
| 135 | |
| 136 | /* restore r8->r15 */ |
| 137 | mov.l @r15+, r8 |
| 138 | mov.l @r15+, r9 |
| 139 | mov.l @r15+, r10 |
| 140 | mov.l @r15+, r11 |
| 141 | mov.l @r15+, r12 |
| 142 | mov.l @r15+, r13 |
| 143 | mov.l @r15+, r14 |
| 144 | mov.l @r15+, r15 |
| 145 | rts |
| 146 | nop |
| 147 | |
| 148 | swap_pages: |
| 149 | bra 1f |
| 150 | mov r4,r0 /* cmd = indirection_page */ |
| 151 | 0: |
| 152 | mov.l @r4+,r0 /* cmd = *ind++ */ |
| 153 | |
| 154 | 1: /* addr = cmd & 0xfffffff0 */ |
| 155 | mov r0,r2 |
| 156 | mov #-16,r1 |
| 157 | and r1,r2 |
| 158 | |
| 159 | /* if(cmd & IND_DESTINATION) dst = addr */ |
| 160 | tst #1,r0 |
| 161 | bt 2f |
| 162 | bra 0b |
| 163 | mov r2,r5 |
| 164 | |
| 165 | 2: /* else if(cmd & IND_INDIRECTION) ind = addr */ |
| 166 | tst #2,r0 |
| 167 | bt 3f |
| 168 | bra 0b |
| 169 | mov r2,r4 |
| 170 | |
| 171 | 3: /* else if(cmd & IND_DONE) return */ |
| 172 | tst #4,r0 |
| 173 | bt 4f |
| 174 | rts |
| 175 | nop |
| 176 | |
| 177 | 4: /* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */ |
| 178 | tst #8,r0 |
| 179 | bt 0b |
| 180 | |
| 181 | mov.l 10f,r3 /* PAGE_SIZE */ |
| 182 | shlr2 r3 |
| 183 | shlr2 r3 |
| 184 | 5: |
| 185 | dt r3 |
| 186 | |
| 187 | /* regular kexec just overwrites the destination page |
| 188 | * with the contents of the source page. |
| 189 | * for the kexec jump case we need to swap the contents |
| 190 | * of the pages. |
| 191 | * to keep it simple swap the contents for both cases. |
| 192 | */ |
| 193 | mov.l @(0, r2), r8 |
| 194 | mov.l @(0, r5), r1 |
| 195 | mov.l r8, @(0, r5) |
| 196 | mov.l r1, @(0, r2) |
| 197 | |
| 198 | mov.l @(4, r2), r8 |
| 199 | mov.l @(4, r5), r1 |
| 200 | mov.l r8, @(4, r5) |
| 201 | mov.l r1, @(4, r2) |
| 202 | |
| 203 | mov.l @(8, r2), r8 |
| 204 | mov.l @(8, r5), r1 |
| 205 | mov.l r8, @(8, r5) |
| 206 | mov.l r1, @(8, r2) |
| 207 | |
| 208 | mov.l @(12, r2), r8 |
| 209 | mov.l @(12, r5), r1 |
| 210 | mov.l r8, @(12, r5) |
| 211 | mov.l r1, @(12, r2) |
| 212 | |
| 213 | add #16,r5 |
| 214 | add #16,r2 |
| 215 | bf 5b |
| 216 | |
| 217 | bra 0b |
| 218 | nop |
| 219 | |
| 220 | .align 2 |
| 221 | 10: |
| 222 | .long PAGE_SIZE |
| 223 | 11: |
| 224 | .long 0 |
| 225 | 12: |
| 226 | .long 0x20000000 ! RB=1 |
| 227 | |
| 228 | relocate_new_kernel_end: |
| 229 | |
| 230 | .globl relocate_new_kernel_size |
| 231 | relocate_new_kernel_size: |
| 232 | .long relocate_new_kernel_end - relocate_new_kernel |