On 25-02-28, Sascha Hauer wrote:
> 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 <[email protected]>
> ---
> 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.
The ROM is checking only the sha sum or does the ROM also have some kind
of signature-checking (pub/priv keys requried)?
Regards,
Marco
> +
> 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
>
>
>
