Bootloaders

> The code I downloaded from psyent works for the dev. kits.

> What's it going to take to port them to my boards?

You'll need to do the following:

1. Copy an existing board source tree to your own tree. E.g.:

--copy: board/psyent/common ==> board/xyzcorp/common

--copy: board/psyent/pk1c20 ==> board/xyzcorp/myboard

2. Rename the main board source file in board/xyzcorp/myboard:

--rename: board/xyzcorp/myboard/pk1c20.c ==> board/xyzcorp/myboard/myboard.c

3. Create a configuration header file in include/configs:

--copy: include/configs/PK1C20.h ==> include/configs/MYBOARD.h

4. Add an entry in the top-level Makefile for your new board. Here it's

handy to simply copy 'n' edit another entry (e.g. PK1C20). E.g.:

MYBOARD_config : unconfig

@./mkconfig MYBOARD nios2 nios2 myboard xyzcorp

5. make distclean; make MYBOARD_config; make

6. If all goes well, you can now start customizing for your specific hardware

in include/configs/MYBOARD.h & in your board's tree. The config editing is

mostly setting base addresses & removing definitions for hardware you

don't have.

> What will it take to support a new comms mode?

u-boot is command-line based. If "uart emulation" is acceptable,

you can just replace a few low-level routines with your own.

E.g. serial_putc(), serial_getc().

> I'll probably only need this for downloading, not for console use.

To initiate a download, u-boot will require a command (e.g. loads,

loadb, tftpboot, etc). As long as your comms link can send a command

to get things started, you shouldn't have a problem.

Regards,

--Scott