diff options
Diffstat (limited to 'arch/sh/kernel/relocate_kernel.S')
| -rw-r--r-- | arch/sh/kernel/relocate_kernel.S | 203 |
1 files changed, 168 insertions, 35 deletions
diff --git a/arch/sh/kernel/relocate_kernel.S b/arch/sh/kernel/relocate_kernel.S index c66cb3209db..fcc9934fb97 100644 --- a/arch/sh/kernel/relocate_kernel.S +++ b/arch/sh/kernel/relocate_kernel.S @@ -4,6 +4,8 @@ * * LANDISK/sh4 is supported. Maybe, SH archtecture works well. * + * 2009-03-18 Magnus Damm - Added Kexec Jump support + * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ @@ -16,23 +18,141 @@ relocate_new_kernel: /* r4 = indirection_page */ /* r5 = reboot_code_buffer */ /* r6 = start_address */ - /* r7 = vbr_reg */ - mov.l 10f,r8 /* PAGE_SIZE */ - mov.l 11f,r9 /* P2SEG */ + 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 */ - /* stack setting */ - add r8,r5 - mov r5,r15 + 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 */ + mov r4,r0 /* cmd = indirection_page */ 0: mov.l @r4+,r0 /* cmd = *ind++ */ -1: /* addr = (cmd | P2SEG) & 0xfffffff0 */ +1: /* addr = cmd & 0xfffffff0 */ mov r0,r2 - or r9,r2 mov #-16,r1 and r1,r2 @@ -40,57 +160,70 @@ relocate_new_kernel: tst #1,r0 bt 2f bra 0b - mov r2,r5 + mov r2,r5 2: /* else if(cmd & IND_INDIRECTION) ind = addr */ tst #2,r0 bt 3f bra 0b - mov r2,r4 + mov r2,r4 -3: /* else if(cmd & IND_DONE) goto 6 */ +3: /* else if(cmd & IND_DONE) return */ tst #4,r0 bt 4f - bra 6f - nop + rts + nop 4: /* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */ tst #8,r0 bt 0b - mov r8,r3 + mov.l 10f,r3 /* PAGE_SIZE */ shlr2 r3 shlr2 r3 5: dt r3 - mov.l @r2+,r1 /* 16n+0 */ - mov.l r1,@r5 - add #4,r5 - mov.l @r2+,r1 /* 16n+4 */ - mov.l r1,@r5 - add #4,r5 - mov.l @r2+,r1 /* 16n+8 */ - mov.l r1,@r5 - add #4,r5 - mov.l @r2+,r1 /* 16n+12 */ - mov.l r1,@r5 - add #4,r5 + + /* 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 -6: -#ifdef CONFIG_SH_STANDARD_BIOS - ldc r7, vbr -#endif - jmp @r6 - nop + nop .align 2 10: .long PAGE_SIZE 11: - .long P2SEG + .long 0 +12: + .long 0x20000000 ! RB=1 relocate_new_kernel_end: |