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Diffstat (limited to 'doc/README.nand')
| -rw-r--r-- | doc/README.nand | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/doc/README.nand b/doc/README.nand index 0f2bdc5cc4..cd7608cf7f 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -1,5 +1,9 @@ NAND FLASH commands and notes + +See NOTE below!!! + + # (C) Copyright 2003 # Dave Ellis, SIXNET, dge@sixnetio.com # @@ -173,3 +177,34 @@ More Definitions: #define NAND_ChipID_UNKNOWN 0x00 #define NAND_MAX_FLOORS 1 #define NAND_MAX_CHIPS 1 + + + +NOTE: +===== + +We now use a complete rewrite of the NAND code based on what is in +2.6.12 Linux kernel. + +The old NAND handling code has been re-factored and is now confined +to only board-specific files and - unfortunately - to the DoC code +(see below). A new configuration variable has been introduced: +CFG_NAND_LEGACY, which has to be defined in the board config file if +that board uses legacy code. If CFG_NAND_LEGACY is defined, the board +specific config.mk file should also have "BOARDLIBS = +drivers/nand_legacy/libnand_legacy.a". For boards using the new NAND +approach (PPChameleon and netstar at the moment) no variable is +necessary, but the config.mk should have "BOARDLIBS = +drivers/nand/libnand.a". + +The necessary changes have been made to all affected boards, and no +build breakage has been introduced, except for NETTA and NETTA_ISDN +targets from MAKEALL. This is due to the fact that these two boards +use JFFS, which has been adopted to use the new NAND, and at the same +time use NAND in legacy mode. The breakage will disappear when the +board-specific code is changed to the new NAND. + +As mentioned above, the legacy code is still used by the DoC subsystem. +The consequence of this is that the legacy NAND can't be removed from +the tree until the DoC is ported to use the new NAND support (or boards +with DoC will break). |