diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.falcon | 13 | ||||
| -rw-r--r-- | doc/README.generic-board | 2 | ||||
| -rw-r--r-- | doc/README.gpt | 14 |
3 files changed, 21 insertions, 8 deletions
diff --git a/doc/README.falcon b/doc/README.falcon index 6357b1e..82a254b 100644 --- a/doc/README.falcon +++ b/doc/README.falcon @@ -80,6 +80,19 @@ spl_start_uboot() : required Returns "0" if SPL should start the kernel, "1" if U-Boot must be started. +Environment variables +--------------------- + +A board may chose to look at the environment for decisions about falcon +mode. In this case the following variables may be supported: + +boot_os : Set to yes/Yes/true/True/1 to enable booting to OS, + any other value to fall back to U-Boot (including + unset) +falcon_args_file : Filename to load as the 'args' portion of falcon mode + rather than the hard-coded value. +falcon_image_file : Filename to load as the OS image portion of falcon + mode rather than the hard-coded value. Using spl command ----------------- diff --git a/doc/README.generic-board b/doc/README.generic-board index 50d3a26..17da0b9 100644 --- a/doc/README.generic-board +++ b/doc/README.generic-board @@ -17,7 +17,7 @@ architecture-specific board.c file before October 2014. Background ---------- -U-Boot has tranditionally had a board.c file for each architecture. This has +U-Boot has traditionally had a board.c file for each architecture. This has introduced quite a lot of duplication, with each architecture tending to do initialisation slightly differently. To address this, a new 'generic board init' feature was introduced a year ago in March 2013 (further motivation is diff --git a/doc/README.gpt b/doc/README.gpt index f822894..ec0156d 100644 --- a/doc/README.gpt +++ b/doc/README.gpt @@ -66,14 +66,14 @@ GPT brief explanation: |Partition n | | | ---------------------------------------------------------- - LBA -34 |Entry 1|Entry 2| Entry 3| Entry 4| Secondary - -------------------------------------------------- (bkp) - LBA -33 |Entries 5 - 128 | GPT + LBA -34 |Entry 1|Entry 2| Entry 3| Entry 4| Backup + -------------------------------------------------- GPT + LBA -33 |Entries 5 - 128 | | | | | LBA -2 | | -------------------------------------------------- - LBA -1 |Secondary GPT Header | + LBA -1 |Backup GPT Header | ---------------------------------------------------------- For a legacy reasons, GPT's LBA 0 sector has a MBR structure. It is called @@ -86,7 +86,7 @@ It is possible to define 128 linearly placed partition entries. "LBA -1" means the last addressable block (in the mmc subsystem: "dev_desc->lba - 1") -Primary/Secondary GPT header: +Primary/Backup GPT header: ---------------------------- Offset Size Description @@ -115,7 +115,7 @@ IMPORTANT: GPT headers and partition entries are protected by CRC32 (the POSIX CRC32). -Primary GPT header and Secondary GPT header have swapped values of "Current LBA" +Primary GPT header and Backup GPT header have swapped values of "Current LBA" and "Backup LBA" and therefore different CRC32 check-sum. CRC32 for GPT headers (field "CRC of header") are calculated up till @@ -125,7 +125,7 @@ CRC32 for partition entries (field "CRC32 of partition array") is calculated for the whole array entry ( Number_of_partition_entries * sizeof(partition_entry_size (usually 128))) -Observe, how Secondary GPT is placed in the memory. It is NOT a mirror reflect +Observe, how Backup GPT is placed in the memory. It is NOT a mirror reflect of the Primary. Partition Entry Format: |