[S] Change in coreboot[main]: vendorcode/google/chromeos: Add API for Chromebook Plus check

[Subrata Banik (Code Review)]

Subrata Banik has submitted this change. ( https://review.coreboot.org/c/coreboot/+/79763?usp=email )

Change subject: vendorcode/google/chromeos: Add API for Chromebook Plus check
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vendorcode/google/chromeos: Add API for Chromebook Plus check

This patch implements an API which relies on the
chromeos_get_factory_config() function to retrieve the factory
config value.

This information is useful to determine whether a ChromeOS device
is branded as a Chromebook Plus based on specific bit flags:

- Bit 4 (0x10): Indicates whether the device chassis has the
                  "chromebook-plus" branding.
   - Bits 3-0 (0x1): Must be 0x1 to signify compliance with
    	   Chromebook Plus hardware specifications.

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

Change-Id: Iebaed1c60e34af4cc36316f1f87a89df778b0857
Signed-off-by: Subrata Banik 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79763
Tested-by: build bot (Jenkins) 
Reviewed-by: Kapil Porwal 
---
M src/vendorcode/google/chromeos/chromeos.h
M src/vendorcode/google/chromeos/tpm_factory_config.c
2 files changed, 38 insertions(+), 0 deletions(-)

Approvals:
  Kapil Porwal: Looks good to me, approved
  build bot (Jenkins): Verified

diff --git a/src/vendorcode/google/chromeos/chromeos.h b/src/vendorcode/google/chromeos/chromeos.h
index c14af31..0c5e4f7 100644
--- a/src/vendorcode/google/chromeos/chromeos.h
+++ b/src/vendorcode/google/chromeos/chromeos.h
@@ -32,6 +32,18 @@
  * Return `-1` in case of error.
  */
 int64_t chromeos_get_factory_config(void);
+/*
+ * Determines whether a ChromeOS device is branded as a Chromebook Plus
+ * based on specific bit flags:
+ *
+ * - Bit 4 (0x10): Indicates whether the device chassis has the
+ *                 "chromebook-plus" branding.
+ * - Bits 3-0 (0x1): Must be 0x1 to signify compliance with Chromebook Plus
+ *                   hardware specifications.
+ *
+ * To be considered a Chromebook Plus, either of these conditions needs to be met.
+ */
+bool chromeos_device_branded_plus(void);

/*
  * Declaration for mainboards to use to generate ACPI-specific ChromeOS needs.
diff --git a/src/vendorcode/google/chromeos/tpm_factory_config.c b/src/vendorcode/google/chromeos/tpm_factory_config.c
index 3b68020..4f8801a 100644
--- a/src/vendorcode/google/chromeos/tpm_factory_config.c
+++ b/src/vendorcode/google/chromeos/tpm_factory_config.c
@@ -2,8 +2,13 @@

#include <console/console.h>
 #include <security/tpm/tss.h>
+#include <types.h>
 #include <vendorcode/google/chromeos/chromeos.h>

+#define CHROMEBOOK_PLUS_HARD_BRANDED BIT(4)
+#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)
 {
    static int64_t factory_config = -1;
@@ -29,3 +34,24 @@

return factory_config;
 }
+
+/*
+ * Determines whether a ChromeOS device is branded as a Chromebook Plus
+ * based on specific bit flags:
+ *
+ * - Bit 4 (0x10): Indicates whether the device chassis has the
+ *                 "chromebook-plus" branding.
+ * - Bits 3-0 (0x1): Must be 0x1 to signify compliance with Chromebook Plus
+ *                   hardware specifications.
+ *
+ * To be considered a Chromebook Plus, either of these conditions needs to be met.
+ */
+bool chromeos_device_branded_plus(void)
+{
+	int64_t factory_config = chromeos_get_factory_config();
+
+	if (factory_config < 0)
+		return false;
+
+	return factory_config & CHROMEBOOK_PLUS_DEVICE;
+}