New patch to review for coreboot: 9be651d baytrail: add way to load reference code from vboot area

[Aaron Durbin]

Aaron Durbin ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/5023

-gerrit

commit 9be651d751788dd54b63483c43491403695fdb47
Author: Aaron Durbin 
Date:   Fri Dec 13 13:05:24 2013 -0800

baytrail: add way to load reference code from vboot area

When employing vboot firmware verification the reference
    code loading should load from the verified firmware
    section. Add this ability.

BUG=chrome-os-partner:22867
    BRANCH=None
    TEST=Built and booted rambi. Noted firmware being loaded
         from rw verified area. Also noted S3 resume loading
         from cached area.

Change-Id: I114de844f218b7573cf90107e174bf0962fdaa50
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://chromium-review.googlesource.com/180026
    Reviewed-by: Shawn Nematbakhsh 
---
 src/soc/intel/baytrail/refcode.c | 62 +++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 11 deletions(-)

diff --git a/src/soc/intel/baytrail/refcode.c b/src/soc/intel/baytrail/refcode.c
index 85bc2bb..019e0a5 100644
--- a/src/soc/intel/baytrail/refcode.c
+++ b/src/soc/intel/baytrail/refcode.c
@@ -24,6 +24,7 @@
 #include <cpu/x86/tsc.h>
 #include <rmodule.h>
 #include <ramstage_cache.h>
+#include <vendorcode/google/chromeos/vboot_handoff.h>

#include <baytrail/ramstage.h>
 #include <baytrail/efi_wrapper.h>
@@ -105,20 +106,63 @@ static void cache_refcode(const struct rmod_stage_load *rsl)
    memcpy(&c->program[0], (void *)c->load_address, c->size);
 }

-static efi_wrapper_entry_t load_refcode_from_cbfs(void)
+static int load_refcode_from_vboot(struct rmod_stage_load *refcode,
+				    struct cbfs_stage *stage)
 {
+	printk(BIOS_DEBUG, "refcode loading from vboot rw area.\n");
+
+	if (rmodule_stage_load(refcode, stage) || refcode->entry == NULL) {
+		printk(BIOS_DEBUG, "Error loading reference code.\n");
+		return -1;
+	}
+	return 0;
+}
+
+static int load_refcode_from_cbfs(struct rmod_stage_load *refcode)
+{
+	printk(BIOS_DEBUG, "refcode loading from cbfs.\n");
+
+	if (rmodule_stage_load_from_cbfs(refcode) || refcode->entry == NULL) {
+		printk(BIOS_DEBUG, "Error loading reference code.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static efi_wrapper_entry_t load_reference_code(void)
+{
+	struct vboot_handoff *vboot_handoff;
+	const struct firmware_component *fwc;
    struct rmod_stage_load refcode = {
    	.cbmem_id = CBMEM_ID_REFCODE,
-		.name = "fallback/refcode",
+		.name = CONFIG_CBFS_PREFIX "/refcode",
    };
+	int ret;

-	printk(BIOS_DEBUG, "refcode loading from cbfs.\n");
+	if (is_s3_resume()) {
+		return load_refcode_from_cache();
+	}

-	if (rmodule_stage_load_from_cbfs(&refcode) || refcode.entry == NULL) {
-		printk(BIOS_DEBUG, "Error loading reference code.\n");
-		return NULL;
+	vboot_handoff = cbmem_find(CBMEM_ID_VBOOT_HANDOFF);
+	fwc = &vboot_handoff->components[CONFIG_VBOOT_REFCODE_INDEX];
+
+	if (vboot_handoff == NULL ||
+	    vboot_handoff->selected_firmware == VB_SELECT_FIRMWARE_READONLY ||
+	    CONFIG_VBOOT_REFCODE_INDEX >= MAX_PARSED_FW_COMPONENTS ||
+	    fwc->size == 0 || fwc->address == 0) {
+		ret = load_refcode_from_cbfs(&refcode);
+	} else {
+		ret = load_refcode_from_vboot(&refcode, (void *)fwc->address);
+
+		if (ret < 0)
+			ret = load_refcode_from_cbfs(&refcode);
    }

+	if (ret < 0)
+		return NULL;
+
+	/* Cache loaded reference code. */
    cache_refcode(&refcode);

return refcode.entry;
@@ -133,11 +177,7 @@ void baytrail_run_reference_code(void)
    	.console_out = send_to_console,
    };

-	if (is_s3_resume()) {
-		entry = load_refcode_from_cache();
-	} else {
-		entry = load_refcode_from_cbfs();
-	}
+	entry = load_reference_code();

if (entry == NULL)
    	return;