From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Schwingen Date: Fri, 02 Nov 2007 21:53:26 +0100 Subject: [U-Boot-Users] Mixing CFI and non-CFI flashs? Message-ID: <472B8E46.7000808@discworld.dascon.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi, I am currently porting u-boot to multiple IXP425-based boards that have accumulated here over the time. One of them has a slight problem, because it uses a combination of two flash roms: - one 8-bit SST 39VF020 boot flash on a 8-bit chip select as boot flash - one 16-bit Intel 64MBit flash on a 16-bit chip select. The intel flash is CFI, while the SST flash is not. I want to use both flash roms, and I want to use as much of the existing flash code as possible. It seems that when using the CFI code, there is no easy way to add a non-CFI flash - right? What would be the best way to use both flash roms? I have come up with: (1) provide a hook in cfi_flash.c to insert hardcoded values into the flash_info structure for the non-CFI flash rom. Due to differences between CFI-AMD and non-CFI AMD flash command cycles, I need to add a new commandset (eg. CFI_CMDSET_AMD_LEGACY) plus a bit of handler code. (2) rename all external-visible functions in flash_cfi.c and add wrapper functions that call either the CFI code or my own code for the non-CFI flash. This has the disadvantage that I need to duplicate code that is already present in cfi_flash.c, but is not exported. I have ssen this done on one chip vendor's u-boot port, and it does not really look nice. (3) extend the code in cfi_flash.c so that external functions can be added via function pointers for non-CFI flashs. Same disadvantage as (2). I have implemented solution (1) now, and it seems to work quite well, with minimal code needed in the board-setup file, but maybe there are better ways to do this - comments? cu Michael