[U-Boot-Users] RAM vs. ROM version of ppcboot
Hi all,
I hope it's right to post questions about PPCBoot at U-Boot mailing list. I'm new at PPCBoot, but know about internals of ARMBoot. So I know the ROM and RAM versions of ARMBoot have to differ.
Now, I plan to download PPCBoot into the RAM of a TQM850L via gdb and run from there. Gdb init the target processor inclusive address decoder. Can I load a ppcboot binary builded from plain tarball into the RAM or schould I swap some configs in include/configs/TQM850L.h ?
thanks, Stephan
In message 02120313135706.06014@pcj86.jena.mazet.de you wrote:
I hope it's right to post questions about PPCBoot at U-Boot mailing list. I'm
Given the fact that PPCBoot has been laid to rest, yes.
new at PPCBoot, but know about internals of ARMBoot. So I know the ROM and RAM versions of ARMBoot have to differ.
Ummm... you don;t need a "RAM version" at all.
Now, I plan to download PPCBoot into the RAM of a TQM850L via gdb and run from there. Gdb init the target processor inclusive address decoder. Can I load a ppcboot binary builded from plain tarball into the RAM or schould I swap some configs in include/configs/TQM850L.h ?
Why would you want to do this? U-Boot (and PPCBoot) is running perfectly fine from flash on all TQ boards. Why would you want to create a "RAM version"? It makes no sense to me.
As the CPU starts executing code from the boot device (CS0 = typically flash) this is the most natural mode to run PPCBoot, too. It was written to expect a CPU coming up from reset, so don't force it into any other environment without a good reason and a very good understanding of what you do, and why.
Since you ask this question, I think you should NOT try doing this.
Best regards,
Wolfgang Denk
Am Dienstag, 3. Dezember 2002 13:55 schrieb Wolfgang Denk:
In message 02120313135706.06014@pcj86.jena.mazet.de you wrote:
I hope it's right to post questions about PPCBoot at U-Boot mailing list. I'm
Given the fact that PPCBoot has been laid to rest, yes.
Yes I know. My running project will be using PPCBoot anymore.
new at PPCBoot, but know about internals of ARMBoot. So I know the ROM and RAM versions of ARMBoot have to differ.
Ummm... you don;t need a "RAM version" at all.
Now, I plan to download PPCBoot into the RAM of a TQM850L via gdb and run from there. Gdb init the target processor inclusive address decoder. Can I load a ppcboot binary builded from plain tarball into the RAM or schould I swap some configs in include/configs/TQM850L.h ?
Why would you want to do this? U-Boot (and PPCBoot) is running perfectly fine from flash on all TQ boards. Why would you want to create a "RAM version"? It makes no sense to me.
I'm using TQ board for studies and learn to swim. The final PPCBoot will be running at my own plattform which is similar to TQ. So I plan to clone the TQ board in PPCBoot and change something in flash.c and tqm8xx.c.
Why RAM version? Hmm, after hardware production my own target has no code at flash. So I could download an ppcboot into flash via debugger, but my VisionCLICK from Windriver doesn't know about the flash briks at my own target (ha, TQ boards too :-). The last chance I have is to use my MPCBDM. But til now I don't know abot flash access via MPCBDM. There is no further doc and I have no time for try'n error.
Thus I plan to use ppcboot running from ram and download / burn to flash itself.
But for all that: Is there any step by step manual how to use the MPCBDM flash facility? Where can I found HOWTOs or FAQs about PPCBoot debugging via gdb (MPCBDM).
Thanks and best regards, Stephan
As the CPU starts executing code from the boot device (CS0 = typically flash) this is the most natural mode to run PPCBoot, too. It was written to expect a CPU coming up from reset, so don't force it into any other environment without a good reason and a very good understanding of what you do, and why.
Since you ask this question, I think you should NOT try doing this.
Best regards,
Wolfgang Denk
participants (2)
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Stephan Linz -
Wolfgang Denk