diff options
Diffstat (limited to 'src/arch/arm64/stage_entry.S')
| -rw-r--r-- | src/arch/arm64/stage_entry.S | 57 |
1 files changed, 29 insertions, 28 deletions
diff --git a/src/arch/arm64/stage_entry.S b/src/arch/arm64/stage_entry.S index 4c26f65707..2d4b26dac9 100644 --- a/src/arch/arm64/stage_entry.S +++ b/src/arch/arm64/stage_entry.S @@ -20,6 +20,16 @@ #include <arch/asm.h> +#if CONFIG_ARM64_CPUS_START_IN_EL3 +#define SCTLR_ELx sctlr_el3 +#elif CONFIG_ARM64_CPUS_START_IN_EL2 +#define SCTLR_ELx sctlr_el2 +#elif CONFIG_ARM64_CPUS_START_IN_EL1 +#define SCTLR_ELx sctlr_el1 +#else +#error Need to know what ELx processor starts up in. +#endif + ENTRY(seed_stack) /* * Initialize the stack to a known value. This is used to check for @@ -43,19 +53,12 @@ load_stack: .quad _stack ENDPROC(seed_stack) -ENTRY(arm64_el3_startup) - /* Set all bits in SCTLR_EL3 to 0 except RES1 and RES0 */ - mrs x0, SCTLR_EL3 - ldr x1, .SCTLR_MASK - and x0, x0, x1 - msr SCTLR_EL3, x0 - /* Set all bits in SCR_EL3 to 0 except RES1 and RES0 */ - mrs x0, SCR_EL3 - ldr x1, .SCR_MASK - and x0, x0, x1 - msr SCR_EL3, x0 - - /* Initialize SP_EL3 as exception stack */ +/* + * Boot strap the processor into a C environemnt. That consists of providing + * 16-byte aligned stack. The programming enviroment uses SP_EL0 as its main + * stack while keeping SP_ELx reserved for exception entry. + */ +ENTRY(arm64_c_environment) ldr x0, .exception_stack_top cmp x0, #0 b.eq 2f @@ -80,27 +83,25 @@ ENTRY(arm64_el3_startup) br x1 .align 4 - .SCTLR_MASK: - .quad 0x0FFFFEFF0 - - .SCR_MASK: - .quad 0x0FFFFC070 - .align 4 - /* - * By default branch to main() and initialize the stack according - * to the Kconfig option for cpu0. However, this code can be relocated - * and reused to start up secondary cpus. - */ .exception_stack_top: .quad CONFIG_EXCEPTION_STACK_TOP .stack_top: .quad _estack .entry: .quad seed_stack -ENDPROC(arm64_el3_startup) -.global arm64_el3_startup_end -arm64_el3_startup_end: +ENDPROC(arm64_c_environment) + +CPU_RESET_ENTRY(arm64_cpu_startup) + mrs x0, SCTLR_ELx + bic x0, x0, #(1 << 25) /* Little Endian */ + bic x0, x0, #(1 << 19) /* XN not enforced */ + bic x0, x0, #(1 << 12) /* Disable Instruction Cache */ + bic x0, x0, #0xf /* Clear SA, C, A, and M */ + msr SCTLR_ELx, x0 + isb + b arm64_c_environment +ENDPROC(arm64_cpu_startup) ENTRY(stage_entry) - b arm64_el3_startup + b arm64_cpu_startup ENDPROC(stage_entry) |