X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=README;h=dc10e4e494b685ae24e5d49575fb52fd20f6c4a3;hb=85fc970d74d09f33fcdcc649e73c5dc4f5334605;hp=8abaf6473f723281c4029b1f738a5a1ee5020947;hpb=d56b4b19744c314c26dc77585a7c7a9253d1487d;p=people%2Fms%2Fu-boot.git diff --git a/README b/README index 8abaf6473f..dc10e4e494 100644 --- a/README +++ b/README @@ -3412,76 +3412,6 @@ following configurations: Builds up envcrc with the target environment so that external utils may easily extract it and embed it in final U-Boot images. -- CONFIG_ENV_IS_IN_FLASH: - - Define this if the environment is in flash memory. - - a) The environment occupies one whole flash sector, which is - "embedded" in the text segment with the U-Boot code. This - happens usually with "bottom boot sector" or "top boot - sector" type flash chips, which have several smaller - sectors at the start or the end. For instance, such a - layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In - such a case you would place the environment in one of the - 4 kB sectors - with U-Boot code before and after it. With - "top boot sector" type flash chips, you would put the - environment in one of the last sectors, leaving a gap - between U-Boot and the environment. - - - CONFIG_ENV_OFFSET: - - Offset of environment data (variable area) to the - beginning of flash memory; for instance, with bottom boot - type flash chips the second sector can be used: the offset - for this sector is given here. - - CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. - - - CONFIG_ENV_ADDR: - - This is just another way to specify the start address of - the flash sector containing the environment (instead of - CONFIG_ENV_OFFSET). - - - CONFIG_ENV_SECT_SIZE: - - Size of the sector containing the environment. - - - b) Sometimes flash chips have few, equal sized, BIG sectors. - In such a case you don't want to spend a whole sector for - the environment. - - - CONFIG_ENV_SIZE: - - If you use this in combination with CONFIG_ENV_IS_IN_FLASH - and CONFIG_ENV_SECT_SIZE, you can specify to use only a part - of this flash sector for the environment. This saves - memory for the RAM copy of the environment. - - It may also save flash memory if you decide to use this - when your environment is "embedded" within U-Boot code, - since then the remainder of the flash sector could be used - for U-Boot code. It should be pointed out that this is - STRONGLY DISCOURAGED from a robustness point of view: - updating the environment in flash makes it always - necessary to erase the WHOLE sector. If something goes - wrong before the contents has been restored from a copy in - RAM, your target system will be dead. - - - CONFIG_ENV_ADDR_REDUND - CONFIG_ENV_SIZE_REDUND - - These settings describe a second storage area used to hold - a redundant copy of the environment data, so that there is - a valid backup copy in case there is a power failure during - a "saveenv" operation. - -BE CAREFUL! Any changes to the flash layout, and some changes to the -source code will make it necessary to adapt /u-boot.lds* -accordingly! - - - CONFIG_ENV_IS_IN_NVRAM: Define this if you have some non-volatile memory device @@ -3634,75 +3564,12 @@ BE CAREFUL! For some special cases, the local device can not use environment stored in a remote NOR flash by SRIO or PCIE link, but it can not erase, write this NOR flash by SRIO or PCIE interface. -- CONFIG_ENV_IS_IN_NAND: - - Define this if you have a NAND device which you want to use - for the environment. - - - CONFIG_ENV_OFFSET: - - CONFIG_ENV_SIZE: - - These two #defines specify the offset and size of the environment - area within the first NAND device. CONFIG_ENV_OFFSET must be - aligned to an erase block boundary. - - - CONFIG_ENV_OFFSET_REDUND (optional): - - This setting describes a second storage area of CONFIG_ENV_SIZE - size used to hold a redundant copy of the environment data, so - that there is a valid backup copy in case there is a power failure - during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be - aligned to an erase block boundary. - - - CONFIG_ENV_RANGE (optional): - - Specifies the length of the region in which the environment - can be written. This should be a multiple of the NAND device's - block size. Specifying a range with more erase blocks than - are needed to hold CONFIG_ENV_SIZE allows bad blocks within - the range to be avoided. - - - CONFIG_ENV_OFFSET_OOB (optional): - - Enables support for dynamically retrieving the offset of the - environment from block zero's out-of-band data. The - "nand env.oob" command can be used to record this offset. - Currently, CONFIG_ENV_OFFSET_REDUND is not supported when - using CONFIG_ENV_OFFSET_OOB. - - CONFIG_NAND_ENV_DST Defines address in RAM to which the nand_spl code should copy the environment. If redundant environment is used, it will be copied to CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. -- CONFIG_ENV_IS_IN_UBI: - - Define this if you have an UBI volume that you want to use for the - environment. This has the benefit of wear-leveling the environment - accesses, which is important on NAND. - - - CONFIG_ENV_UBI_PART: - - Define this to a string that is the mtd partition containing the UBI. - - - CONFIG_ENV_UBI_VOLUME: - - Define this to the name of the volume that you want to store the - environment in. - - - CONFIG_ENV_UBI_VOLUME_REDUND: - - Define this to the name of another volume to store a second copy of - the environment in. This will enable redundant environments in UBI. - It is assumed that both volumes are in the same MTD partition. - - - CONFIG_UBI_SILENCE_MSG - - CONFIG_UBIFS_SILENCE_MSG - - You will probably want to define these to avoid a really noisy system - when storing the env in UBI. - - CONFIG_ENV_IS_IN_FAT: Define this if you want to use the FAT file system for the environment. @@ -3734,57 +3601,6 @@ but it can not erase, write this NOR flash by SRIO or PCIE interface. - CONFIG_FAT_WRITE: This must be enabled. Otherwise it cannot save the environment file. -- CONFIG_ENV_IS_IN_MMC: - - Define this if you have an MMC device which you want to use for the - environment. - - - CONFIG_SYS_MMC_ENV_DEV: - - Specifies which MMC device the environment is stored in. - - - CONFIG_SYS_MMC_ENV_PART (optional): - - Specifies which MMC partition the environment is stored in. If not - set, defaults to partition 0, the user area. Common values might be - 1 (first MMC boot partition), 2 (second MMC boot partition). - - - CONFIG_ENV_OFFSET: - - CONFIG_ENV_SIZE: - - These two #defines specify the offset and size of the environment - area within the specified MMC device. - - If offset is positive (the usual case), it is treated as relative to - the start of the MMC partition. If offset is negative, it is treated - as relative to the end of the MMC partition. This can be useful if - your board may be fitted with different MMC devices, which have - different sizes for the MMC partitions, and you always want the - environment placed at the very end of the partition, to leave the - maximum possible space before it, to store other data. - - These two values are in units of bytes, but must be aligned to an - MMC sector boundary. - - - CONFIG_ENV_OFFSET_REDUND (optional): - - Specifies a second storage area, of CONFIG_ENV_SIZE size, used to - hold a redundant copy of the environment data. This provides a - valid backup copy in case the other copy is corrupted, e.g. due - to a power failure during a "saveenv" operation. - - This value may also be positive or negative; this is handled in the - same way as CONFIG_ENV_OFFSET. - - This value is also in units of bytes, but must also be aligned to - an MMC sector boundary. - - - CONFIG_ENV_SIZE_REDUND (optional): - - This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is - set. If this value is set, it must be set to the same value as - CONFIG_ENV_SIZE. - Please note that the environment is read-only until the monitor has been relocated to RAM and a RAM copy of the environment has been created; also, when using EEPROM you will have to use getenv_f()