Traditionally we call __mmu_cache_flush in early startup. There is a problem with armv7 and hierarchical caches though, on these systems __mmu_cache_flush uses the stack. Appearantly this was seldomly a problem, because most of these systems have a ROM bootloader which sets up some stack, but on a special i.MX6 system this failed badly. We should not have to flush caches here. Every sane system should pass control to the bootloader without stale entries in the caches *), so it should be a safe assumption that the cache flush can be removed.
Since __mmu_cache_flush is not called from early code anymore we can also move it to the regular text section. Be brave and give it a try. *) omap3 seems to be a exception to this, but this has a cache flush in arch_init_lowlevel already Signed-off-by: Sascha Hauer <[email protected]> --- arch/arm/cpu/cache-armv4.S | 1 - arch/arm/cpu/cache-armv5.S | 1 - arch/arm/cpu/cache-armv6.S | 1 - arch/arm/cpu/cache-armv7.S | 1 - arch/arm/cpu/start.c | 6 ------ 5 files changed, 10 deletions(-) diff --git a/arch/arm/cpu/cache-armv4.S b/arch/arm/cpu/cache-armv4.S index fc53653..6d03565 100644 --- a/arch/arm/cpu/cache-armv4.S +++ b/arch/arm/cpu/cache-armv4.S @@ -42,7 +42,6 @@ ENTRY(__mmu_cache_off) mov pc, lr ENDPROC(__mmu_cache_off) -__BARE_INIT ENTRY(__mmu_cache_flush) mrc p15, 0, r6, c0, c0 @ get processor ID mov r2, #64*1024 @ default: 32K dcache size (*2) diff --git a/arch/arm/cpu/cache-armv5.S b/arch/arm/cpu/cache-armv5.S index d870e6b..a1193a6 100644 --- a/arch/arm/cpu/cache-armv5.S +++ b/arch/arm/cpu/cache-armv5.S @@ -42,7 +42,6 @@ ENTRY(__mmu_cache_off) mov pc, lr ENDPROC(__mmu_cache_off) -__BARE_INIT ENTRY(__mmu_cache_flush) 1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate D cache bne 1b diff --git a/arch/arm/cpu/cache-armv6.S b/arch/arm/cpu/cache-armv6.S index 9de76da..335bac2 100644 --- a/arch/arm/cpu/cache-armv6.S +++ b/arch/arm/cpu/cache-armv6.S @@ -44,7 +44,6 @@ ENTRY(__mmu_cache_off) #endif mov pc, lr -__BARE_INIT ENTRY(__mmu_cache_flush) mov r1, #0 mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D diff --git a/arch/arm/cpu/cache-armv7.S b/arch/arm/cpu/cache-armv7.S index 416498d..28a6315 100644 --- a/arch/arm/cpu/cache-armv7.S +++ b/arch/arm/cpu/cache-armv7.S @@ -50,7 +50,6 @@ ENTRY(__mmu_cache_off) mov pc, r12 ENDPROC(__mmu_cache_off) -__BARE_INIT ENTRY(__mmu_cache_flush) mrc p15, 0, r10, c0, c1, 5 @ read ID_MMFR1 tst r10, #0xf << 16 @ hierarchical cache (ARMv7) diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c index 0fcc950..f2f6173 100644 --- a/arch/arm/cpu/start.c +++ b/arch/arm/cpu/start.c @@ -75,12 +75,6 @@ void __naked __bare_init reset(void) #ifdef CONFIG_ARCH_HAS_LOWLEVEL_INIT arch_init_lowlevel(); #endif - __asm__ __volatile__ ( - "bl __mmu_cache_flush;" - : - : - : "r0", "r1", "r2", "r3", "r6", "r10", "r12", "lr", "cc", "memory" - ); /* disable MMU stuff and caches */ r = get_cr(); -- 1.7.10 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
