crossystem: Add board_id property

futility is one of a few places in ChromeOS that uses "mosys platform
version".  The goal is to remove this command from mosys.

This commit adds a new property to crossystem, "board_id", which
reads the board revision from SMBIOS/FDT, and replaces the call in
futility with the appropriate VbGetSystemPropertyInt.

BUG=b:187790074
BRANCH=none
TEST="crossystem board_id" on hana and brya

Change-Id: Id69c8e309c0e509a165aa6da2778573ac7de3455
Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4029537
Reviewed-by: Julius Werner <jwerner@chromium.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/host/arch/x86/lib/crossystem_arch.c b/host/arch/x86/lib/crossystem_arch.c
index e6bd7e31..f3e631ad 100644
--- a/host/arch/x86/lib/crossystem_arch.c
+++ b/host/arch/x86/lib/crossystem_arch.c
@@ -83,6 +83,10 @@
 #define GPIO_BASE_PATH "/sys/class/gpio"
 #define GPIO_EXPORT_PATH GPIO_BASE_PATH "/export"
 
+/* Base for SMBIOS information files */
+#define SMBIOS_BASE_PATH "/sys/class/dmi/id"
+#define SMBIOS_PRODUCT_VERSION_PATH SMBIOS_BASE_PATH "/product_version"
+
 /* Filename for NVRAM file */
 #define NVRAM_PATH "/dev/nvram"
 
@@ -834,6 +838,25 @@ static int ReadGpio(unsigned signal_type)
 	return (value == active_high ? 1 : 0);
 }
 
+static int GetBoardId(void)
+{
+	/*
+	 * Can't use vb2_read_file here, as it expects to be able to
+	 * seek to the end of the file to tell the size, and the sysfs
+	 * SMBIOS implementation will seek to offset 4096.
+	 */
+	int board_id = -1;
+	FILE *f = fopen(SMBIOS_PRODUCT_VERSION_PATH, "r");
+
+	if (!f)
+		return -1;
+
+	if (fscanf(f, "rev%d\n", &board_id) != 1)
+		board_id = -1;
+
+	fclose(f);
+	return board_id;
+}
 
 int VbGetArchPropertyInt(const char* name)
 {
@@ -897,6 +920,9 @@ int VbGetArchPropertyInt(const char* name)
 			value = (int)fwupdate_value;
 	}
 
+	if (!strcasecmp(name, "board_id"))
+		return GetBoardId();
+
 	return value;
 }