Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9090
-gerrit
commit e2659c9f0bfacb49a30005b7d2b6fd636eae14e5 Author: Aaron Durbin adurbin@chromium.org Date: Thu Sep 18 13:48:49 2014 -0500
arm64: provide entry points for BSP and non-BSP
It's helpful to differentiate the startup paths for the BSP and the non-BSP. Therefore have c_entry be an 2 element array of function pointers. The non-BSP paths have an entry point one instruction after stage/module entry.
BUG=chrome-os-partner:30785 BRANCH=None TEST=Built and booted to kernel.
Change-Id: I40bb40462906f1b1eaf2db8584985095e8ac0bae Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: ce10f954041b3fd581ad8a3d82dee567b68637fe Original-Change-Id: Ia573b1095dca5f69e371bf1ddf6b6df72fa3b52e Original-Signed-off-by: Aaron Durbin adurbin@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/218844 Original-Reviewed-by: Furquan Shaikh furquan@chromium.org --- src/arch/arm64/c_entry.c | 21 +++++++++------------ src/arch/arm64/include/arch/stages.h | 18 +++++++++++++++--- src/arch/arm64/stage_entry.S | 32 +++++++++++++++++++++++++++----- 3 files changed, 51 insertions(+), 20 deletions(-)
diff --git a/src/arch/arm64/c_entry.c b/src/arch/arm64/c_entry.c index f4a9848..5e3dfe8 100644 --- a/src/arch/arm64/c_entry.c +++ b/src/arch/arm64/c_entry.c @@ -24,13 +24,6 @@ #include <arch/stages.h> #include "cpu-internal.h"
-/* - * This variable holds entry point for CPUs starting up. Before the other - * CPUs are brought up this value will change to provide the secondary - * code path. - */ -void (*c_entry)(void) = &arm64_init; - void __attribute__((weak)) arm64_soc_init(void) { /* Default weak implementation does nothing. */ @@ -54,7 +47,7 @@ static void seed_stack(void) *slot++ = 0xdeadbeefdeadbeefULL; }
-void arm64_init(void) +static void arm64_init(void) { cpu_set_bsp(); seed_stack(); @@ -71,11 +64,15 @@ static void secondary_cpu_start(void) arch_secondary_cpu_init(); }
+/* + * This variable holds entry point for CPUs starting up. The first + * element is the BSP path, and the second is the non-BSP path. + */ +void (*c_entry[2])(void) = { &arm64_init, &secondary_cpu_start }; + extern void arm64_cpu_startup(void); + void *prepare_secondary_cpu_startup(void) { - c_entry = &secondary_cpu_start; - dcache_clean_invalidate_by_mva(c_entry, sizeof(c_entry)); - - return &arm64_cpu_startup; + return secondary_entry_point(&arm64_cpu_startup); } diff --git a/src/arch/arm64/include/arch/stages.h b/src/arch/arm64/include/arch/stages.h index 9771492..fd633e4 100644 --- a/src/arch/arm64/include/arch/stages.h +++ b/src/arch/arm64/include/arch/stages.h @@ -20,18 +20,30 @@ #ifndef __ARCH_STAGES_H #define __ARCH_STAGES_H
+#include <stdint.h> + extern void main(void);
void stage_entry(void); void stage_exit(void *); void jmp_to_elf_entry(void *entry, unsigned long buffer, unsigned long size);
-/* C entry point for all arm64 stages. */ -void arm64_init(void); - /* This function is called upon initial entry of each stage. It is called prior * to main(). That means all of the common infrastructure will most likely not * be available to be used (such as console). */ void arm64_soc_init(void);
+/* + * Stages and rmodules have 2 entry points: BSP and non-BSP. Provided + * a pointer the correct non-BSP entry point will be returned. The + * first instruction is for BSP and the 2nd is for non-BSP. Instructions + * are all 32-bit on arm64. + */ +static inline void *secondary_entry_point(void *e) +{ + uintptr_t nonbsp = (uintptr_t)e; + + return (void *)(nonbsp + sizeof(uint32_t)); +} + #endif diff --git a/src/arch/arm64/stage_entry.S b/src/arch/arm64/stage_entry.S index 6b8ca7b..5a5ddab 100644 --- a/src/arch/arm64/stage_entry.S +++ b/src/arch/arm64/stage_entry.S @@ -105,6 +105,8 @@ ENTRY(arm64_c_environment)
/* Get entry point by dereferencing c_entry. */ ldr x1, 1f + /* Retrieve entry in c_entry array using x26 as the index. */ + adds x1, x1, x26, lsl #3 ldr x1, [x1] /* Move back the arguments from x25 to x0 */ mov x0, x25 @@ -114,14 +116,28 @@ ENTRY(arm64_c_environment) .quad c_entry ENDPROC(arm64_c_environment)
+/* The first 2 instructions are for BSP and secondary CPUs, + * respectively. x26 holds the index into c_entry array. */ +.macro split_bsp_path + b 2000f + b 2001f + 2000: + mov x26, #0 + b 2002f + 2001: + mov x26, #1 + 2002: +.endm + ENTRY(__rmodule_entry) + split_bsp_path /* Save the arguments to secmon in x25 */ - mov x25, x0 - b arm64_c_environment + mov x25, x0 + b arm64_c_environment ENDPROC(__rmodule_entry)
-CPU_RESET_ENTRY(arm64_cpu_startup) - read_current x0, sctlr +ENTRY(_arm64_cpu_startup) + read_current x0, sctlr bic x0, x0, #(1 << 25) /* Little Endian */ bic x0, x0, #(1 << 19) /* XN not enforced */ bic x0, x0, #(1 << 12) /* Disable Instruction Cache */ @@ -129,8 +145,14 @@ CPU_RESET_ENTRY(arm64_cpu_startup) write_current sctlr, x0, x1 isb b arm64_c_environment +ENDPROC(_arm64_cpu_startup) + +CPU_RESET_ENTRY(arm64_cpu_startup) + split_bsp_path + b _arm64_cpu_startup ENDPROC(arm64_cpu_startup)
ENTRY(stage_entry) - b arm64_cpu_startup + split_bsp_path + b _arm64_cpu_startup ENDPROC(stage_entry)
-
Patrick Georgi