Questions about the U-Boot README, esp. CFG_IMMR
I got another question
About CFG_IMMR the README says: DO NOT CHANGE! (MPC8xx systems only)
This confuses me. As the IMMR is a SPR (special purpose register) in the MPC8xx, assigning it an address seems to make no sense.
Nevertheless CFG_IMMR is used everywhere in the U-Boot code, so there must be a preset for it, which I can't find in the source. Also, almost any config in include/configs sets this to 0xFF000000.
So what is it good for and what should I choose?
Peter Asemann
Quoted 2 lines · In message <[email protected]> you wrote:
About
CFG_IMMRthe README says: DO NOT CHANGE! (MPC8xx systems only)
This is a bit of strong language to scare off thos who don't unterstand what they are doing.
Quoted 2 lines
This confuses me. As the IMMR is a SPR (special purpose register) in the MPC8xx, assigning it an address seems to make no sense.
Read this as: special register which holds the address of the Internem Memory.
Quoted 2 lines
Nevertheless
CFG_IMMRis used everywhere in the U-Boot code, so there must be a preset for it, which I can't find in the source. Also, almost
RTFM - the 'M' is the MPC8xx User's Manual here.
Quoted 2 lines
any config in
include/configssets this to0xFF000000. So what is it good for and what should I choose?
This depends on the memory map you chose for your board. Remember:
it's _you_ who defines the memory map.
Best regards,
Wolfgang Denk
Signature · 3 lines
Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de A list is only as strong as its weakest link. -- Don Knuth