This adds the Kconfig option CONFIG_ARCH_K3_AUTHENTICATE_IMAGE. When
enabled, the full barebox image will only be started when it can be
authenticated using the ROM API.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
arch/arm/mach-k3/Kconfig | 7 ++++++
arch/arm/mach-k3/r5.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 70 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-k3/Kconfig b/arch/arm/mach-k3/Kconfig
index 37d5155577..e93e3154c8 100644
--- a/arch/arm/mach-k3/Kconfig
+++ b/arch/arm/mach-k3/Kconfig
@@ -37,6 +37,13 @@ config MACH_BEAGLEPLAY
help
Say Y here if you are using a TI AM62x based BeaglePlay board
+config ARCH_K3_AUTHENTICATE_IMAGE
+ bool "Force authentication of FIP image against ROM API"
+ help
+ By enabling this option the FIP image loaded by the first stage
+ will be authenticated against the K3 ROM API. Images which fail
+ to authenticate will not be started.
+
config ARCH_K3_COMMAND_AUTHENTICATE
bool "k3_authenticate_image command"
depends on COMMAND_SUPPORT
diff --git a/arch/arm/mach-k3/r5.c b/arch/arm/mach-k3/r5.c
index c8a91e2597..d0093a3be7 100644
--- a/arch/arm/mach-k3/r5.c
+++ b/arch/arm/mach-k3/r5.c
@@ -244,6 +244,64 @@ static uuid_t uuid_ti_dm_fw = UUID_TI_DM_FW;
static uuid_t uuid_bl33 = UUID_NON_TRUSTED_FIRMWARE_BL33;
static uuid_t uuid_bl32 = UUID_SECURE_PAYLOAD_BL32;
+static struct fip_state *fip_image_load_auth(const char *filename, size_t offset)
+{
+ struct fip_state *fip = NULL;
+ int fd;
+ unsigned int maxsize = SZ_4M;
+ size_t size;
+ void *buf = NULL;
+ int ret;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return ERR_PTR(-errno);
+
+ if (offset) {
+ loff_t pos;
+ pos = lseek(fd, offset, SEEK_SET);
+ if (pos < 0) {
+ ret = -errno;
+ goto err;
+ }
+ }
+
+ buf = xzalloc(maxsize);
+
+ /*
+ * There is no easy way to determine the size of the certificates the ROM
+ * takes as images, so the best we can do here is to assume a maximum size
+ * and load this.
+ */
+ ret = read_full(fd, buf, maxsize);
+ if (ret < 0)
+ goto err;
+
+ size = maxsize;
+
+ ret = k3_authenticate_image(&buf, &size);
+ if (ret) {
+ pr_err("Failed to authenticate %s\n", filename);
+ goto err;
+ }
+
+ fip = fip_new();
+ ret = fip_parse_buf(fip, buf, size, NULL);
+ if (ret)
+ goto err;
+
+ close(fd);
+
+ return fip;
+err:
+ if (fip)
+ fip_free(fip);
+ close(fd);
+ free(buf);
+
+ return ERR_PTR(ret);
+}
+
static int load_fip(const char *filename, off_t offset)
{
struct fip_state *fip;
@@ -251,7 +309,11 @@ static int load_fip(const char *filename, off_t offset)
unsigned char shasum[SHA256_DIGEST_SIZE];
int ret;
- fip = fip_image_open(filename, offset);
+ if (IS_ENABLED(CONFIG_ARCH_K3_AUTHENTICATE_IMAGE))
+ fip = fip_image_load_auth(filename, offset);
+ else
+ fip = fip_image_open(filename, offset);
+
if (IS_ERR(fip)) {
pr_err("Cannot open FIP image: %pe\n", fip);
return PTR_ERR(fip);
--
2.39.5
