diff options
Diffstat (limited to 'arch/arm/boot/compressed/head.S')
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index fe4d9c3ad76..75189f13cf5 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -11,6 +11,7 @@ #include <linux/linkage.h> #include <asm/assembler.h> + .arch armv7-a /* * Debugging stuff * @@ -141,7 +142,6 @@ start: mov r7, r1 @ save architecture ID mov r8, r2 @ save atags pointer -#ifndef __ARM_ARCH_2__ /* * Booting from Angel - need to enter SVC mode and disable * FIQs/IRQs (numeric definitions from angel arm.h source). @@ -157,10 +157,6 @@ not_angel: safe_svcmode_maskall r0 msr spsr_cxsf, r9 @ Save the CPU boot mode in @ SPSR -#else - teqp pc, #0x0c000003 @ turn off interrupts -#endif - /* * Note that some cache flushing and other stuff may * be needed here - is there an Angel SWI call for this? @@ -182,7 +178,19 @@ not_angel: ldr r4, =zreladdr #endif - bl cache_on + /* + * Set up a page table only if it won't overwrite ourself. + * That means r4 < pc && r4 - 16k page directory > &_end. + * Given that r4 > &_end is most unfrequent, we add a rough + * additional 1MB of room for a possible appended DTB. + */ + mov r0, pc + cmp r0, r4 + ldrcc r0, LC0+32 + addcc r0, r0, pc + cmpcc r4, r0 + orrcc r4, r4, #1 @ remember we skipped cache_on + blcs cache_on restart: adr r0, LC0 ldmia r0, {r1, r2, r3, r6, r10, r11, r12} @@ -228,7 +236,7 @@ restart: adr r0, LC0 * r0 = delta * r2 = BSS start * r3 = BSS end - * r4 = final kernel address + * r4 = final kernel address (possibly with LSB set) * r5 = appended dtb size (still unknown) * r6 = _edata * r7 = architecture ID @@ -276,6 +284,7 @@ restart: adr r0, LC0 */ cmp r0, #1 sub r0, r4, #TEXT_OFFSET + bic r0, r0, #1 add r0, r0, #0x100 mov r1, r6 sub r2, sp, r6 @@ -322,12 +331,13 @@ dtb_check_done: /* * Check to see if we will overwrite ourselves. - * r4 = final kernel address + * r4 = final kernel address (possibly with LSB set) * r9 = size of decompressed image * r10 = end of this image, including bss/stack/malloc space if non XIP * We basically want: * r4 - 16k page directory >= r10 -> OK * r4 + image length <= address of wont_overwrite -> OK + * Note: the possible LSB in r4 is harmless here. */ add r10, r10, #16384 cmp r4, r10 @@ -389,7 +399,8 @@ dtb_check_done: add sp, sp, r6 #endif - bl cache_clean_flush + tst r4, #1 + bleq cache_clean_flush adr r0, BSYM(restart) add r0, r0, r6 @@ -401,7 +412,7 @@ wont_overwrite: * r0 = delta * r2 = BSS start * r3 = BSS end - * r4 = kernel execution address + * r4 = kernel execution address (possibly with LSB set) * r5 = appended dtb size (0 if not present) * r7 = architecture ID * r8 = atags pointer @@ -464,6 +475,15 @@ not_relocated: mov r0, #0 cmp r2, r3 blo 1b + /* + * Did we skip the cache setup earlier? + * That is indicated by the LSB in r4. + * Do it now if so. + */ + tst r4, #1 + bic r4, r4, #1 + blne cache_on + /* * The C runtime environment should now be setup sufficiently. * Set up some pointers, and start decompressing. @@ -512,6 +532,7 @@ LC0: .word LC0 @ r1 .word _got_start @ r11 .word _got_end @ ip .word .L_user_stack_end @ sp + .word _end - restart + 16384 + 1024*1024 .size LC0, . - LC0 #ifdef CONFIG_ARCH_RPC @@ -805,8 +826,8 @@ call_cache_fn: adr r12, proc_types .align 2 .type proc_types,#object proc_types: - .word 0x00000000 @ old ARM ID - .word 0x0000f000 + .word 0x41000000 @ old ARM ID + .word 0xff00f000 mov pc, lr THUMB( nop ) mov pc, lr |