Currently, there are a bunch of boards which enable the UEFI capsule update feature. The actual update of the firmware images is done through the dfu framework which uses the dfu_alt_info environment variable for getting information on the update, like device, partition number/address etc. The dfu framework allows the variable to be set through the set_dfu_alt_info function defined by the platform, or if the function is not defined, it gets the variable from the environment. Using the value set in the environment is not very robust, since the variable can be modified from the u-boot command line and this can cause an incorrect update.
To prevent this from happening, define the set_dfu_alt_info function when the capsule update feature is enabled. A weak function is defined which sets the dfu_alt_info environment variable by getting the string for the variable from the platform.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V4: * Define a weak function set_dfu_alt_info for setting the variable in a non board specific file as suggested by Ilias * Drop the definitions of set_dfu_alt_info that were being added in the board files
lib/efi_loader/Kconfig | 2 ++ lib/efi_loader/efi_firmware.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+)
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index e5e35fe51f..09fb8cbe75 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -174,6 +174,7 @@ config EFI_CAPSULE_FIRMWARE_FIT depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT select UPDATE_FIT select DFU + select SET_DFU_ALT_INFO select EFI_CAPSULE_FIRMWARE help Select this option if you want to enable firmware management protocol @@ -185,6 +186,7 @@ config EFI_CAPSULE_FIRMWARE_RAW depends on SANDBOX || (!SANDBOX && !EFI_CAPSULE_FIRMWARE_FIT) select DFU_WRITE_ALT select DFU + select SET_DFU_ALT_INFO select EFI_CAPSULE_FIRMWARE help Select this option if you want to enable firmware management protocol diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c index e9fc4b9c1e..cbfa57f64f 100644 --- a/lib/efi_loader/efi_firmware.c +++ b/lib/efi_loader/efi_firmware.c @@ -11,9 +11,11 @@ #include <dfu.h> #include <efi_loader.h> #include <image.h> +#include <memalign.h> #include <signatures.h>
#include <linux/list.h> +#include <linux/sizes.h>
#define FMP_PAYLOAD_HDR_SIGNATURE SIGNATURE_32('M', 'S', 'S', '1')
@@ -35,6 +37,27 @@ struct fmp_payload_header { u32 lowest_supported_version; };
+#define DFU_ALT_BUF_LEN SZ_1K + +__weak void set_dfu_alt_info(char *interface, char *devstr) +{ + int n; + const char *dfu_alt_info; + ALLOC_CACHE_ALIGN_BUFFER(char, buf, DFU_ALT_BUF_LEN); + + if (!CONFIG_IS_ENABLED(EFI_HAVE_CAPSULE_SUPPORT) && + env_get("dfu_alt_info")) + return; + + dfu_alt_info = update_info.dfu_string; + n = strlen(dfu_alt_info); + memset(buf, 0, n + 1); + + strncpy(buf, dfu_alt_info, n); + + env_set("dfu_alt_info", buf); +} + /* Place holder; not supported */ static efi_status_t EFIAPI efi_firmware_get_image_unsupported(