diff options
| author | Simon Glass <sjg@chromium.org> | 2011-11-05 03:56:51 +0000 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2011-12-09 17:30:09 +0100 |
| commit | 80433c9ac6fd3bd0fe1707a04d9668db4aba1dde (patch) | |
| tree | bb02432e43369953e07cd26b1c29beb8c32f3828 | |
| parent | 210576fc5e5d323c8039f95c7b5b2c7512a550e4 (diff) | |
arm: Move CP15 init out of cpu_init_crit()
Some SOCs have do not start up with their 'main' CPU. The first U-Boot
code may then be executed with a CPU which does not have a CP15, or not a
useful one.
Here we split the initialization of CP15 into a separate call, which can
be performed later if required.
Once the main CPU is running, you should call cpu_init_cp15() to perform
this init as early as possible.
Existing ARMv7 boards which define CONFIG_SKIP_LOWLEVEL_INIT should not
need to change, this CP15 init is still skipped in that case. The only
impact for these boards is that the cpu_init_cp15() will be available
even if it is never used on these boards.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
| -rw-r--r-- | arch/arm/cpu/armv7/start.S | 24 | ||||
| -rw-r--r-- | arch/arm/include/asm/u-boot-arm.h | 3 |
2 files changed, 21 insertions, 6 deletions
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index d23dc9d719..b05be6cc94 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -162,6 +162,7 @@ reset: /* the mask ROM code should have PLL and others stable */ #ifndef CONFIG_SKIP_LOWLEVEL_INIT + bl cpu_init_cp15 bl cpu_init_crit #endif @@ -299,17 +300,16 @@ jump_2_ram: _board_init_r_ofs: .word board_init_r - _start - -#ifndef CONFIG_SKIP_LOWLEVEL_INIT /************************************************************************* * - * CPU_init_critical registers + * cpu_init_cp15 * - * setup important registers - * setup memory timing + * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless + * CONFIG_SYS_ICACHE_OFF is defined. * *************************************************************************/ -cpu_init_crit: +.globl cpu_init_cp15 +cpu_init_cp15: /* * Invalidate L1 I/D */ @@ -334,7 +334,19 @@ cpu_init_crit: orr r0, r0, #0x00001000 @ set bit 12 (I) I-cache #endif mcr p15, 0, r0, c1, c0, 0 + mov pc, lr @ back to my caller + +#ifndef CONFIG_SKIP_LOWLEVEL_INIT +/************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + *************************************************************************/ +cpu_init_crit: /* * Jump to board specific initialization... * The Mask ROM will have already initialized diff --git a/arch/arm/include/asm/u-boot-arm.h b/arch/arm/include/asm/u-boot-arm.h index d3308f7a81..4ca75f9f93 100644 --- a/arch/arm/include/asm/u-boot-arm.h +++ b/arch/arm/include/asm/u-boot-arm.h @@ -46,6 +46,9 @@ extern ulong IRQ_STACK_START_IN; /* 8 bytes in IRQ stack */ int cpu_init(void); int cleanup_before_linux(void); +/* Set up ARMv7 MMU, caches and TLBs */ +void cpu_init_cp15(void); + /* cpu/.../arch/cpu.c */ int arch_cpu_init(void); int arch_misc_init(void); |