From f692c5814ea5c7ff4895576e1db8361ff3b7d9fb Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Wed, 27 Aug 2014 15:52:01 -0500 Subject: [PATCH] arm64: add indirection to C entry point To allow setting the entry point for the secondary CPUs provide a pointer, c_entry, which contains the location to branc to after setting up the stack. BUG=chrome-os-partner:31545 BRANCH=None TEST=Built and booted to the kernel on ryu. Change-Id: Ic2f6c79cde708b24c379345aed1e2cc0760ccad8 Signed-off-by: Aaron Durbin Reviewed-on: https://chromium-review.googlesource.com/214771 Reviewed-by: Furquan Shaikh --- src/arch/arm64/c_entry.c | 8 ++++++++ src/arch/arm64/stage_entry.S | 8 +++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/src/arch/arm64/c_entry.c b/src/arch/arm64/c_entry.c index f08a5853f4..3e9d44e4af 100644 --- a/src/arch/arm64/c_entry.c +++ b/src/arch/arm64/c_entry.c @@ -20,6 +20,14 @@ #include #include + +/* + * 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. */ diff --git a/src/arch/arm64/stage_entry.S b/src/arch/arm64/stage_entry.S index 86136555dc..e323de5d96 100644 --- a/src/arch/arm64/stage_entry.S +++ b/src/arch/arm64/stage_entry.S @@ -99,7 +99,13 @@ ENTRY(arm64_c_environment) bl cpu_get_stack mov sp, x0 - b arm64_init + /* Get entry point by dereferencing c_entry. */ + ldr x0, 1f + ldr x0, [x0] + br x0 +.align 3 + 1: + .quad c_entry ENDPROC(arm64_c_environment) CPU_RESET_ENTRY(arm64_cpu_startup)