Comio,
We working to make Uboot our preferred Linux bootloader and for that matter a good general purpose boot loader.
The 547x and 548x families are actually based on the MPC8220(i) which is in the Uboot tree.
So actually...
You (we) need to take the 8220(i) and merge it with the V4 ColdFire tree coming out in the next release of Uboot.
Wolfgang pointed out some good stuff. We (Freescale) have plans to put out a Uboot for 547x, but it probably won't get done for a couple of months. We'd be happy to work with you as we did the 8220(i) port originally.
The key is that the 547x and 548x ColdFire parts use a micro-coded DMA engine. So it is probably easier to get the FEC (ethernet) and DMA drivers from the 8220 code base.
Actually the following could be re-used from 8220(i)
DMA microcode
FEC (ethernet)
PSC (Uart)
FlexBus (which is the local bus)
DDR (SDRAM memory controller)
PCI support
The cache, USB, and IRQ controllers are different. Those will need to be created. As the USB is only a device only...it may have little reason to support in Uboot.
Let us know your thoughts.
-JWW