libpayload: add support for vboot_handoff

The vboot_handoff structure needs to be parsed from the coreboot tables.
Add a placeholder in sysinfo as well as the ability to parse the
coreboot table entry concering the vboot_handoff structure.

Built with unified boot loader and ebuild changes. Can find and use
the VbInitParams for doing kernel selection.

Change-Id: If40a863b4a445fa5f7814325add03355fd0ac647
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2720
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

payloads/libpayload/arch/x86/coreboot.c

@@ -79,6 +79,14 @@ static void cb_parse_serial(void *ptr, struct sysinfo_t *info)
 }
 
 #ifdef CONFIG_CHROMEOS
+static void cb_parse_vboot_handoff(unsigned char *ptr, struct sysinfo_t *info)
+{
+	struct cb_vboot_handoff *vbho = (struct cb_vboot_handoff *)ptr;
+
+	info->vboot_handoff = vbho->vboot_handoff_addr;
+	info->vboot_handoff_size = vbho->vboot_handoff_size;
+}
+
 static void cb_parse_vbnv(unsigned char *ptr, struct sysinfo_t *info)
 {
 	struct cb_vbnv *vbnv = (struct cb_vbnv *)ptr;
@@ -258,6 +266,9 @@ static int cb_parse_header(void *addr, int len, struct sysinfo_t *info)
 		case CB_TAG_VBNV:
 			cb_parse_vbnv(ptr, info);
 			break;
+		case CB_TAG_VBOOT_HANDOFF:
+			cb_parse_vboot_handoff(ptr, info);
+			break;
 #endif
 		case CB_TAG_TIMESTAMPS:
 			cb_parse_tstamp(ptr, info);

payloads/libpayload/include/coreboot_tables.h

@@ -209,6 +209,14 @@ struct cb_vbnv {
 	uint32_t vbnv_size;
 };
 
+#define CB_TAG_VBOOT_HANDOFF	0x0020
+struct cb_vboot_handoff {
+	uint32_t tag;
+	uint32_t size;
+	void *vboot_handoff_addr;
+	uint32_t vboot_handoff_size;
+};
+
 #define CB_TAG_CMOS_OPTION_TABLE 0x00c8
 struct cb_cmos_option_table {
 	u32 tag;

payloads/libpayload/include/sysinfo.h

@@ -88,6 +88,8 @@ struct sysinfo_t {
 	struct cb_mainboard *mainboard;
 
 #ifdef CONFIG_CHROMEOS
+	void	*vboot_handoff;
+	u32	vboot_handoff_size;
 	void	*vdat_addr;
 	u32	vdat_size;
 #endif