Flash programming on the INCA-IP board is complicated because of the
  EBU swapping unit. A BDI2000 can be used for flash programming only
  if the EBU swapping unit is enabled; otherwise it will not detect the
  flash memory. But the EBU swapping unit is disadbled after reset, so
  if you program some code to flash with the swapping unit on, it will
  not be runnable with the swapping unit off.
  
  The consequence is that you have to write a pre-swapped image to
  flash using the BDI2000. A simple host-side tool "inca-swap-bytes" is
  provided in the "tools/" directory. Use it as follows:
  
  	bash$ ./inca-swap-bytes <u-boot.bin >u-boot.bin.swp
  
  Note that the current BDI config file _disables_ the EBU swapping
  unit for the flash bank 0. To enable it, (this is required for the
  BDI flash commands to work) uncomment the following line in the
  config file:
  
  	;WM32   0xb8000260      0x404161ff ; Swapping unit enabled
  
  and comment out
  
  	WM32    0xb8000260      0x004161ff ; Swapping unit disabled
  
  Alternatively, you can use "mm 0xb8000260 <value>" commands to
  enable/disable the swapping unit manually.
  
  Just for reference, here is the complete sequence of actions we took
  to install a U-Boot image into flash.
  
      1. ./inca-swap-bytes <u-boot.bin >u-boot.bin.swp
  
      2. From BDI:
  
  	mm 0xb8000260  0x404161ff
  	erase 0xb0000000
  	erase 0xb0010000
  	prog 0xb0000000 /tftpboot/INCA/u-boot.bin.swp bin
  	mm 0xb8000260 0x004161ff
  	go 0xb0000000

  
  Ethernet autonegotiation needs some time to complete. Instead of
  delaying the boot process in all cases, we just start the
  autonegotiation process when U-Boot comes up and that is all. Most
  likely, it will complete by the time the network transfer is
  attempted for the first time. In the worst case, if a transfer is
  attempted before the autonegotiation is complete, just a single
  packet would be lost resulting in a single timeout error, and then
  the transfer would proceed normally. So the time that we would have
  lost unconditionally waiting for the autonegotiation to complete, we
  have to wait only if the file transfer is started immediately after
  reset. We've verified that this works for all the clock
  configurations.

  (C) 2003 Wolfgang Denk