[S] Change in coreboot[main]: vendorcode/google/chromeos: Use unsigned int for "factory_config"

[Subrata Banik (Code Review)]

Subrata Banik has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/79769?usp=email )

Change subject: vendorcode/google/chromeos: Use unsigned int for "factory_config"
......................................................................

vendorcode/google/chromeos: Use unsigned int for "factory_config"

This patch ensures `chromeos_get_factory_config()` returns an
unsigned integer value because factory config represents
bit-fields to determine the Chromebook Plus branding.

BUG=b:317880956
TEST=Able to verify that google/screebo is branded as
Chromebook Plus.

Change-Id: I3021b8646de4750b4c8e2a2981f42500894fa2d0
Signed-off-by: Subrata Banik 
---
M src/vendorcode/google/chromeos/chromeos.h
M src/vendorcode/google/chromeos/tpm_factory_config.c
2 files changed, 12 insertions(+), 10 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/69/79769/1

diff --git a/src/vendorcode/google/chromeos/chromeos.h b/src/vendorcode/google/chromeos/chromeos.h
index 0c5e4f7..5b8c8a0a 100644
--- a/src/vendorcode/google/chromeos/chromeos.h
+++ b/src/vendorcode/google/chromeos/chromeos.h
@@ -17,6 +17,8 @@
 static inline void reboot_from_watchdog(void) { return; }
 #endif /* CONFIG_CHROMEOS */

+#define CHROMEOS_ERROR	~((uint64_t)0)
+
 /**
  * Perform any platform specific actions required prior to resetting the Cr50.
  * Defined as weak function in cr50_enable_update.c
@@ -29,9 +31,9 @@
 /*
  * The factory config space is a one-time programmable info page.
  * For the unprovisioned one, the read will be 0x0.
- * Return `-1` in case of error.
+ * Return "CHROMEOS_ERROR" in case of error.
  */
-int64_t chromeos_get_factory_config(void);
+uint64_t chromeos_get_factory_config(void);
 /*
  * Determines whether a ChromeOS device is branded as a Chromebook Plus
  * based on specific bit flags:
diff --git a/src/vendorcode/google/chromeos/tpm_factory_config.c b/src/vendorcode/google/chromeos/tpm_factory_config.c
index 4f8801a..022fd48 100644
--- a/src/vendorcode/google/chromeos/tpm_factory_config.c
+++ b/src/vendorcode/google/chromeos/tpm_factory_config.c
@@ -9,11 +9,11 @@
 #define CHROMEBOOK_PLUS_SOFT_BRANDED BIT(0)
 #define CHROMEBOOK_PLUS_DEVICE (CHROMEBOOK_PLUS_HARD_BRANDED | CHROMEBOOK_PLUS_SOFT_BRANDED)

-int64_t chromeos_get_factory_config(void)
+uint64_t chromeos_get_factory_config(void)
 {
-	static int64_t factory_config = -1;
+	static uint64_t factory_config = CHROMEOS_ERROR;

-	if (factory_config >= 0)
+	if (factory_config != CHROMEOS_ERROR)
    	return factory_config;

/* Initialize TPM driver. */
@@ -21,15 +21,15 @@
    if (rc != TPM_SUCCESS) {
    	printk(BIOS_ERR, "%s:%d - tlcl_lib_init() failed: %#x\n",
    	       __func__, __LINE__, rc);
-		return -1;
+		return CHROMEOS_ERROR;
    }

-	rc = tlcl_cr50_get_factory_config((uint64_t *)&factory_config);
+	rc = tlcl_cr50_get_factory_config(&factory_config);

if (rc != TPM_SUCCESS) {
    	printk(BIOS_ERR, "%s:%d - tlcl_cr50_get_factory_config() failed: %#x\n",
    	       __func__, __LINE__, rc);
-		return -1;
+		return CHROMEOS_ERROR;
    }

return factory_config;
@@ -48,9 +48,9 @@
  */
 bool chromeos_device_branded_plus(void)
 {
-	int64_t factory_config = chromeos_get_factory_config();
+	uint64_t factory_config = chromeos_get_factory_config();

-	if (factory_config < 0)
+	if (factory_config == CHROMEOS_ERROR)
    	return false;

return factory_config & CHROMEBOOK_PLUS_DEVICE;