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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.cfi | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/doc/README.cfi b/doc/README.cfi new file mode 100644 index 0000000000..d087ff0d63 --- /dev/null +++ b/doc/README.cfi @@ -0,0 +1,29 @@ +The common CFI driver provides this weak default implementation for +flash_cmd_reset(): + +void __flash_cmd_reset(flash_info_t *info) +{ + /* + * We do not yet know what kind of commandset to use, so we issue + * the reset command in both Intel and AMD variants, in the hope + * that AMD flash roms ignore the Intel command. + */ + flash_write_cmd(info, 0, 0, AMD_CMD_RESET); + flash_write_cmd(info, 0, 0, FLASH_CMD_RESET); +} +void flash_cmd_reset(flash_info_t *info) + __attribute__((weak,alias("__flash_cmd_reset"))); + + +Some flash chips seems to have trouble with this reset sequence. In this case +the board specific code can override this weak default version with a board +specific function. For example the digsy_mtc board equipped with the M29W128GH +from Numonyx needs this version to function properly: + +void flash_cmd_reset(flash_info_t *info) +{ + flash_write_cmd(info, 0, 0, AMD_CMD_RESET); +} + +see also: +http://www.mail-archive.com/u-boot@lists.denx.de/msg24368.html |
