Porting U-Boot to an ARM920T-Based Board.
Hi,
I would like to get some help to port u-boot on a new hardware (the hardware is still under heavy development).
I have listed the following issues which I've encountered while reading the README and browsing the source tree.
1. My board has an ARM920T core. Instinctively, I would choose a "template" board support subdirectory that has the same core. If my platform is very different from the template, can I just choose the board that fits my needs (e.g. UART, FLASH, MEMORY MAP, etc.) and just re-configure the core? If this is possible, how do I do this?
2. My UART port is 16550 compliant. The ARM920T core (cpu/arm920T/) is using a serial.c that is compliant to S3C24XX. Can I just simply overwrite cpu/arm920t/serial.c with 16550 compliant serial.c?
3. Can somebody please tell me the files that are most-likely to change when porting u-boot to a new platform? Currently I am modifying the following:
board/myboard /* copied from board smdk2410 */
- What should be placed here? Initialization routines?
What is the "minimal" requirement for this subdirectory?
Makefile - to make our board noticable to the main kernel tree
include/configs/myboard.h
4. Are there other important files to modify in order to build the proper u-boot image?
Please advise on the stated issues. Thank you very much.
Regards,
Rodel Miguel
Dear Rodel,
Quoted 4 lines · in message <[email protected]> you wrote:
1. My board has an ARM920T core. Instinctively, I would choose a "template" board support subdirectory that has the same core. If my platform is very different from the template, can I just choose the
Please don't ask "can I". Of course you can. _Anything_ can be done. The question is if it makes sense to do it, and how much effort it needs.
Quoted 2 lines
board that fits my needs (e.g. UART, FLASH, MEMORY MAP, etc.) and just re-configure the core? If this is possible, how do I do this?
Yes, you can chose a similar board and re-use it's code. This is what U-Boot is all about.
Quoted 3 lines
2. My UART port is 16550 compliant. The ARM920T core (cpu/arm920T/) is using a
serial.cthat is compliant to S3C24XX. Can I just simply overwritecpu/arm920t/serial.cwith 16550 compliantserial.c?
No, you cannot. You will use the existing code in drivers/serial.c instead.
Quoted 2 lines
3. Can somebody please tell me the files that are most-likely to change when porting u-boot to a new platform? Currently I am
Please read the README.
Quoted 3 lines
board/myboard /* copied from board smdk2410 */
- What should be placed here? Initialization routines?
What is the "minimal" requirement for this subdirectory?
This depends on your requirements. The minimum is the initialization needed to get your board started.
Quoted 2 lines
4. Are there other important files to modify in order to build the proper u-boot image?
Maybe, but unlikely.
Best regards,
Wolfgang Denk
Signature · 7 lines
Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de When a child is taught ... its programmed with simple instructions -- and at some point, if its mind develops properly, it exceeds the sum of what it was taught, thinks independently. -- Dr. Richard Daystrom, "The Ultimate Computer", stardate 4731.3.