[U-Boot-Users] How to set up Am29LV641D flash on MPC5200B

[Edward Jubenville]

I'm having some problems porting U-Boot to a custom board based closely on
the original Freescale Lite5200 IceCube (not the newer Lite5200B).
Specifically, I am having problems getting U-Boot to recognize our flash
memory.

Our board differs from the original design in a few key ways:
- uses MPC5200B processor instead of MPC5200
- the original Freescale design used the Non-MUX 24 address bit / 8 data
bits from the LocalPlus bus, but we operate MUXed with 25 bit address bits
and 16 data bits.
- uses Am29LV641D flash memory instead of Am29LV652D

I am using u-boot-1.1.4, but modified TEXT_BASE to run out of RAM at
0x200000 (which seems to be working fine on our board).

I'm a newbie at u-boot porting, so I may have done something stupid.
Because our design is closer to the original IceCube design than the newer
Lite5200B design, I cloned the board/icecube folder as the starting point of
my new board.  I couldn't get u-boot to reach a command prompt until I read
the Freescale appnote "AN3220 U-Boot Porting Guide", and changed the IPB bus
speed to 133MHz as recommended for the MPC5200B processor.  Other than that,
I built u-boot identically to a Lite5200 board.

At the U-boot prompt, the flinfo command tells me that flash is
unrecognized.  I inspected MBAR+0x300, and it had a value of 0x00047800,
which I interpreted to be correct for an 8-bit bus, not a 16-bit bus.  After
searching the u-boot code for how that gets set, I added this line to my
include/configs/<board>.h file:
	#define CFG_CS0_CFG             0x0004F900
hoping to get flash properly reconfigured for a 16-bit MUXed bus.
After rebuild, inspection of MBAR+0300 showed the new value, but u-boot
still didn't recognize the flash.

Any help, please?

I have a BDI2000, if that would help me find/fix the problem.

Thanks,

Ed Jubenville