diff options
Diffstat (limited to 'arch/sh/kernel/relocate_kernel.S')
| -rw-r--r-- | arch/sh/kernel/relocate_kernel.S | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/arch/sh/kernel/relocate_kernel.S b/arch/sh/kernel/relocate_kernel.S new file mode 100644 index 0000000000..d9bf2b727b --- /dev/null +++ b/arch/sh/kernel/relocate_kernel.S @@ -0,0 +1,230 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * relocate_kernel.S - put the kernel image in place to boot + * 2005.9.17 kogiidena@eggplant.ddo.jp + * + * LANDISK/sh4 is supported. Maybe, SH archtecture works well. + * + * 2009-03-18 Magnus Damm - Added Kexec Jump support + */ +#include <linux/linkage.h> +#include <asm/addrspace.h> +#include <asm/page.h> + + .globl relocate_new_kernel +relocate_new_kernel: + /* r4 = indirection_page */ + /* r5 = reboot_code_buffer */ + /* r6 = start_address */ + + mov.l 10f, r0 /* PAGE_SIZE */ + add r5, r0 /* setup new stack at end of control page */ + + /* save r15->r8 to new stack */ + mov.l r15, @-r0 + mov r0, r15 + mov.l r14, @-r15 + mov.l r13, @-r15 + mov.l r12, @-r15 + mov.l r11, @-r15 + mov.l r10, @-r15 + mov.l r9, @-r15 + mov.l r8, @-r15 + + /* save other random registers */ + sts.l macl, @-r15 + sts.l mach, @-r15 + stc.l gbr, @-r15 + stc.l ssr, @-r15 + stc.l sr, @-r15 + sts.l pr, @-r15 + stc.l spc, @-r15 + + /* switch to bank1 and save r7->r0 */ + mov.l 12f, r9 + stc sr, r8 + or r9, r8 + ldc r8, sr + mov.l r7, @-r15 + mov.l r6, @-r15 + mov.l r5, @-r15 + mov.l r4, @-r15 + mov.l r3, @-r15 + mov.l r2, @-r15 + mov.l r1, @-r15 + mov.l r0, @-r15 + + /* switch to bank0 and save r7->r0 */ + mov.l 12f, r9 + not r9, r9 + stc sr, r8 + and r9, r8 + ldc r8, sr + mov.l r7, @-r15 + mov.l r6, @-r15 + mov.l r5, @-r15 + mov.l r4, @-r15 + mov.l r3, @-r15 + mov.l r2, @-r15 + mov.l r1, @-r15 + mov.l r0, @-r15 + + mov.l r4, @-r15 /* save indirection page again */ + + bsr swap_pages /* swap pages before jumping to new kernel */ + nop + + mova 11f, r0 + mov.l r15, @r0 /* save pointer to stack */ + + jsr @r6 /* hand over control to new kernel */ + nop + + mov.l 11f, r15 /* get pointer to stack */ + mov.l @r15+, r4 /* restore r4 to get indirection page */ + + bsr swap_pages /* swap pages back to previous state */ + nop + + /* make sure bank0 is active and restore r0->r7 */ + mov.l 12f, r9 + not r9, r9 + stc sr, r8 + and r9, r8 + ldc r8, sr + mov.l @r15+, r0 + mov.l @r15+, r1 + mov.l @r15+, r2 + mov.l @r15+, r3 + mov.l @r15+, r4 + mov.l @r15+, r5 + mov.l @r15+, r6 + mov.l @r15+, r7 + + /* switch to bank1 and restore r0->r7 */ + mov.l 12f, r9 + stc sr, r8 + or r9, r8 + ldc r8, sr + mov.l @r15+, r0 + mov.l @r15+, r1 + mov.l @r15+, r2 + mov.l @r15+, r3 + mov.l @r15+, r4 + mov.l @r15+, r5 + mov.l @r15+, r6 + mov.l @r15+, r7 + + /* switch back to bank0 */ + mov.l 12f, r9 + not r9, r9 + stc sr, r8 + and r9, r8 + ldc r8, sr + + /* restore other random registers */ + ldc.l @r15+, spc + lds.l @r15+, pr + ldc.l @r15+, sr + ldc.l @r15+, ssr + ldc.l @r15+, gbr + lds.l @r15+, mach + lds.l @r15+, macl + + /* restore r8->r15 */ + mov.l @r15+, r8 + mov.l @r15+, r9 + mov.l @r15+, r10 + mov.l @r15+, r11 + mov.l @r15+, r12 + mov.l @r15+, r13 + mov.l @r15+, r14 + mov.l @r15+, r15 + rts + nop + +swap_pages: + bra 1f + mov r4,r0 /* cmd = indirection_page */ +0: + mov.l @r4+,r0 /* cmd = *ind++ */ + +1: /* addr = cmd & 0xfffffff0 */ + mov r0,r2 + mov #-16,r1 + and r1,r2 + + /* if(cmd & IND_DESTINATION) dst = addr */ + tst #1,r0 + bt 2f + bra 0b + mov r2,r5 + +2: /* else if(cmd & IND_INDIRECTION) ind = addr */ + tst #2,r0 + bt 3f + bra 0b + mov r2,r4 + +3: /* else if(cmd & IND_DONE) return */ + tst #4,r0 + bt 4f + rts + nop + +4: /* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */ + tst #8,r0 + bt 0b + + mov.l 10f,r3 /* PAGE_SIZE */ + shlr2 r3 + shlr2 r3 +5: + dt r3 + + /* regular kexec just overwrites the destination page + * with the contents of the source page. + * for the kexec jump case we need to swap the contents + * of the pages. + * to keep it simple swap the contents for both cases. + */ + mov.l @(0, r2), r8 + mov.l @(0, r5), r1 + mov.l r8, @(0, r5) + mov.l r1, @(0, r2) + + mov.l @(4, r2), r8 + mov.l @(4, r5), r1 + mov.l r8, @(4, r5) + mov.l r1, @(4, r2) + + mov.l @(8, r2), r8 + mov.l @(8, r5), r1 + mov.l r8, @(8, r5) + mov.l r1, @(8, r2) + + mov.l @(12, r2), r8 + mov.l @(12, r5), r1 + mov.l r8, @(12, r5) + mov.l r1, @(12, r2) + + add #16,r5 + add #16,r2 + bf 5b + + bra 0b + nop + + .align 2 +10: + .long PAGE_SIZE +11: + .long 0 +12: + .long 0x20000000 ! RB=1 + +relocate_new_kernel_end: + + .globl relocate_new_kernel_size +relocate_new_kernel_size: + .long relocate_new_kernel_end - relocate_new_kernel |