diff options
| -rw-r--r-- | boot/Kconfig | 13 | ||||
| -rw-r--r-- | boot/image-fit.c | 24 |
2 files changed, 31 insertions, 6 deletions
diff --git a/boot/Kconfig b/boot/Kconfig index ae6f09a6ede..19a170957c6 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -103,6 +103,19 @@ config FIT_FULL_CHECK of bugs or omissions in the code. This includes a bad structure, multiple root nodes and the like. +config CONTROL_DTB_AS_FIT + bool "Allow U-Boot's control DTB to act as FIT image" + help + Enable this to exempt U-Boot's control DTB from the sanity + checks done to ensure FIT images are valid. This can for + example be used to embed whole scripts in the control DTB, + that can then be invoked using 'source ${fdtcontroladdr}'. + In a secure boot setup, this is safe, as the control DTB is + necessarily covered by any mechanism verifying U-Boot and + can therefore be trusted. This only affects the case where + the image being checked is gd->fdt_blob. See + doc/develop/devicetree/control.rst for details. + config FIT_SIGNATURE bool "Enable signature verification of FIT uImages" depends on DM diff --git a/boot/image-fit.c b/boot/image-fit.c index b0fcaf6e17f..87427d07d7c 100644 --- a/boot/image-fit.c +++ b/boot/image-fit.c @@ -1664,6 +1664,16 @@ static int fdt_check_no_at(const void *fit, int parent) return 0; } +static int fit_check_images_node(const void *fit) +{ + if (fdt_path_offset(fit, FIT_IMAGES_PATH) < 0) { + log_debug("Wrong FIT format: no images parent node\n"); + return -ENOENT; + } + + return 0; +} + int fit_check_format(const void *fit, ulong size) { int ret; @@ -1676,6 +1686,13 @@ int fit_check_format(const void *fit, ulong size) return -ENOEXEC; } + /* + * For the control DTB to act as a FIT image, we only require + * an /images node. + */ + if (CONFIG_IS_ENABLED(CONTROL_DTB_AS_FIT) && fit == gd_fdt_blob()) + return fit_check_images_node(fit); + if (CONFIG_IS_ENABLED(FIT_FULL_CHECK)) { /* * If we are not given the size, make do with calculating it. @@ -1724,12 +1741,7 @@ int fit_check_format(const void *fit, ulong size) } /* mandatory subimages parent '/images' node */ - if (fdt_path_offset(fit, FIT_IMAGES_PATH) < 0) { - log_debug("Wrong FIT format: no images parent node\n"); - return -ENOENT; - } - - return 0; + return fit_check_images_node(fit); } int fit_conf_find_compat(const void *fit, const void *fdt) |