X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=README;h=88ff837d7c984c32fa715c95d0145289eab41b37;hb=eae4b2b67bc8c68e2440616a447ca6c6898ad188;hp=b2eee19773702f002860b133007b65b937d5fa5c;hpb=d5c6144fe326e255e42ec273fc5d88f45cd61548;p=u-boot diff --git a/README b/README index b2eee19773..88ff837d7c 100644 --- a/README +++ b/README @@ -1108,6 +1108,14 @@ The following options need to be configured: XXX - this list needs to get updated! +- Removal of commands + If no commands are needed to boot, you can disable + CONFIG_CMDLINE to remove them. In this case, the command line + will not be available, and when U-Boot wants to execute the + boot command (on start-up) it will call board_run_command() + instead. This can reduce image size significantly for very + simple boot procedures. + - Regular expression support: CONFIG_REGEX If this variable is defined, U-Boot is linked against @@ -1794,7 +1802,7 @@ CBFS (Coreboot Filesystem) support The DIU driver will look for the 'video-mode' environment variable, and if defined, enable the DIU as a console during - boot. See the documentation file README.video for a + boot. See the documentation file doc/README.video for a description of this variable. - LCD Support: CONFIG_LCD @@ -1908,7 +1916,7 @@ CBFS (Coreboot Filesystem) support If this option is set, then U-Boot will prevent the environment variable "splashimage" from being set to a problematic address - (see README.displaying-bmps). + (see doc/README.displaying-bmps). This option is useful for targets where, due to alignment restrictions, an improperly aligned BMP image will cause a data abort. If you think you will not have problems with unaligned @@ -3093,20 +3101,6 @@ CBFS (Coreboot Filesystem) support will set it back to normal. This command currently supports i.MX53 and i.MX6. -- Signing support: - CONFIG_RSA - - This enables the RSA algorithm used for FIT image verification - in U-Boot. See doc/uImage.FIT/signature.txt for more information. - - The Modular Exponentiation algorithm in RSA is implemented using - driver model. So CONFIG_DM needs to be enabled by default for this - library to function. - - The signing part is build into mkimage regardless of this - option. The software based modular exponentiation is built into - mkimage irrespective of this option. - - bootcount support: CONFIG_BOOTCOUNT_LIMIT @@ -3306,33 +3300,14 @@ FIT uImage format: enabled per default for backward compatibility. - FIT image support: - CONFIG_FIT - Enable support for the FIT uImage format. - - CONFIG_FIT_BEST_MATCH - When no configuration is explicitly selected, default to the - one whose fdt's compatibility field best matches that of - U-Boot itself. A match is considered "best" if it matches the - most specific compatibility entry of U-Boot's fdt's root node. - The order of entries in the configuration's fdt is ignored. - - CONFIG_FIT_SIGNATURE - This option enables signature verification of FIT uImages, - using a hash signed and verified using RSA. If - CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive - hashing is available using hardware, RSA library will use it. - See doc/uImage.FIT/signature.txt for more details. - - WARNING: When relying on signed FIT images with required - signature check the legacy image format is default - disabled. If a board need legacy image format support - enable this through CONFIG_IMAGE_FORMAT_LEGACY - CONFIG_FIT_DISABLE_SHA256 Supporting SHA256 hashes has quite an impact on binary size. For constrained systems sha256 hash support can be disabled with this option. + TODO(sjg@chromium.org): Adjust this option to be positive, + and move it to Kconfig + - Standalone program support: CONFIG_STANDALONE_LOAD_ADDR