Change in coreboot[master]: src/lib: Add FW_CONIFG_SOURCE_VPD

[Wonkyu Kim (Code Review)]

Wonkyu Kim has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/58839 )

Change subject: src/lib: Add FW_CONIFG_SOURCE_VPD
......................................................................

src/lib: Add FW_CONIFG_SOURCE_VPD

Read fw_config value from VPD.
This new option can be used where chrome EC is not supported like
pre-silicon platform and fw_config can be updated by VPD tool in OS.

TEST= boot to OS and read fw_config from vpd
1. Boot to OS
2. Write "fw_config" in VPD
   ex)vpd -i "RW_VPD" -s "fw_config"="1"
3. reboot and check fw_config value from coreboot log

Signed-off-by: Wonkyu Kim 
Change-Id: I4df7d5612e18957416a40ab854fa63c8b11b4216
---
M src/Kconfig
M src/lib/fw_config.c
2 files changed, 24 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/39/58839/1

diff --git a/src/Kconfig b/src/Kconfig
index 797819b..a6efceb 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -416,6 +416,16 @@
      local image to preempt the mainboard selected source and and can be used as
      FW_CONFIG_SOURCE_CHROMEEC_CBI fallback option.

+config FW_CONFIG_SOURCE_VPD
+	bool "Obtain Firmware Configuration value from VPD"
+	depends on FW_CONFIG
+	default n
+	help
+	  With this option enabled coreboot will look for the 32bit firmware
+	  configuration value in VPD key name "fw_config".  This option will
+	  override other sources and allow the local image to preempt the mainboard
+	  selected source and can be used for other FW_CONFIG_SOURCEs fallback option.
+
 config HAVE_RAMPAYLOAD
    bool

diff --git a/src/lib/fw_config.c b/src/lib/fw_config.c
index da4269a..71237ac 100644
--- a/src/lib/fw_config.c
+++ b/src/lib/fw_config.c
@@ -11,6 +11,7 @@
 #include <lib.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <drivers/vpd/vpd.h>

uint64_t fw_config_get(void)
 {
@@ -46,6 +47,19 @@
    		       fw_config_value);
    }

+	if (CONFIG(FW_CONFIG_SOURCE_VPD) && fw_config_value == UNDEFINED_FW_CONFIG) {
+		int32_t vpd_value;
+		if (vpd_get_int("fw_config", VPD_RW_THEN_RO, (int *const) &vpd_value)) {
+			fw_config_value = vpd_value;
+			printk(BIOS_INFO, "FW_CONFIG value from VPD is 0x%" PRIx64 "\n",
+			       fw_config_value);
+		} else {
+			printk(BIOS_WARNING, "%s: Could not get fw_config from vpd\n",
+			       __func__);
+			fw_config_value = UNDEFINED_FW_CONFIG;
+		}
+	}
+
    return fw_config_value;
 }