[coreboot-gerrit] New patch to review for coreboot: 4e2eb0c arm64: Switch to EL2 for libpayload jump

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9074

-gerrit

commit 4e2eb0c53d817c457cf5103528043b64ee73d379
Author: Furquan Shaikh <furquan at google.com>
Date:   Thu Sep 11 16:06:01 2014 -0700

    arm64: Switch to EL2 for libpayload jump
    
    CQ-DEPEND=CL:216826,CL:218300
    BUG=chrome-os-partner:31634
    BRANCH=None
    TEST=Compiles successfully and we are able to start execution of libpayload in
    EL2 and reach kernel login prompt
    
    Change-Id: I233f9867470a4723f320dc0dcaa670a56dcf0f5d
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 169948a2afeeb7848daeb37600963bd503527f1a
    Original-Change-Id: I336d73085f08ca03e533555a10b88f20d74b4347
    Original-Signed-off-by: Furquan Shaikh <furquan at google.com>
    Original-Reviewed-on: https://chromium-review.googlesource.com/217826
    Original-Tested-by: Furquan Shaikh <furquan at chromium.org>
    Original-Reviewed-by: Aaron Durbin <adurbin at chromium.org>
    Original-Commit-Queue: Furquan Shaikh <furquan at chromium.org>
---
 src/arch/arm64/boot.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/arch/arm64/boot.c b/src/arch/arm64/boot.c
index 5217a9f..91980fb 100644
--- a/src/arch/arm64/boot.c
+++ b/src/arch/arm64/boot.c
@@ -18,17 +18,36 @@
  */
 
 #include <arch/cache.h>
+#include <arch/lib_helpers.h>
 #include <arch/stages.h>
+#include <arch/transition.h>
 #include <cbmem.h>
 #include <console/console.h>
 #include <program_loading.h>
+#include <string.h>
 
 void arch_payload_run(const struct payload *payload)
 {
 	void (*doit)(void *) = payload->entry;
 	void *cb_tables = cbmem_find(CBMEM_ID_CBTABLE);
+	uint8_t current_el = get_current_el();
 
 	printk(BIOS_SPEW, "entry    = %p\n", payload->entry);
+
+	/* If current EL is not EL3, jump to payload at same EL. */
+	if (current_el != EL3) {
+		cache_sync_instructions();
+		/* Point of no-return */
+		doit(cb_tables);
+	}
+
+	/* If current EL is EL3, we transition to payload in EL2. */
+	struct exc_state exc_state;
+
+	memset(&exc_state, 0, sizeof(exc_state));
+
+	exc_state.elx.spsr = get_eret_el(EL2, SPSR_USE_L);
+
 	cache_sync_instructions();
-	doit(cb_tables);
+	transition_with_entry(payload->entry, cb_tables, &exc_state);
 }