Re: [U-Boot-Users] How much does U-Boot Replace PMON? Anyone w/ opinions? (from embedded newbie)
Andrew -
Thanks so much for your reply and candor - that's kind of what I needed to hear either way.
I'll check out the others you mentioned first, before trying to dive into changing PMON (we already have had to mod PMON, but only changing existing code/regs/etc.)
Sean
--- Andrew Dyer amdyer@gmail.com wrote:
On Feb 8, 2008 1:31 PM, Sean Parker supinlick@yahoo.com wrote:
Hello -
We're using PMC's MSP8510 MIPS processor. Included in
the
BSP was Linux 2.6.18 and PMON2000. We have all running, except the boot from CF. I'm a bit familiar with
GRUB/LILO,
and I'm looking for a direct replacement, and we
thought
we'd be able to use either until we saw GRUB was not
ported
to MIPS.
However it looks lile U-Boot accomplishes both (PMON+GRUB-like functionality) since I see some
indication
U-Boot handles VFAT? (how about ATA CF?) (If U-Boot can read a VFAT CF, and load the linux image from there,
then
that negates the need for any subsequent boot loader
like
GRUB/LILO - right?)
Any recommendations out there? (such as "trash PMON
and
go with U-BOOT - it does all you want" or "look here
xxx to
find what you want")
I would guess it would be easier to add code to boot from ATA to pmon-2000 (never used the -2000 version, just the old pmon a ong time ago) than to do a new port to something not supported (u-boot for mips is not in the best of shape). That being said, we boot a Raza Au1550 MIPS using u-boot off of CF. I believe the s/w guys are using ext2 on the CF instead of vfat, but it does work.
You could also look at MIPS's yamon, Broadcom's CFE, or MicroMonitor (umon) as other bootloader choices.
-- Hardware, n.: The parts of a computer system that can be kicked.
God Bless Sean Parker
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In message 520311.76459.qm@web51905.mail.re2.yahoo.com you wrote:
Thanks so much for your reply and candor - that's kind of what I needed to hear either way.
Well, it would have been much beter if the reply had been sent to the ML so others could have commented on it.
--- Andrew Dyer amdyer@gmail.com wrote:
I would guess it would be easier to add code to boot from ATA to pmon-2000 (never used the -2000 version, just the old pmon a ong time ago) than to do a new port to something not supported (u-boot for mips
Well, if you have a working port for one boot loader which you can look at for init code etc. then coming up with a port of U-Boot is not that hard.
is not in the best of shape). That being said, we boot a
There is a number of MIPS board that are working pretty well - Andrew: what exactly do you mean by "not in the best of shape"?
Raza Au1550 MIPS using u-boot off of CF. I believe the s/w guys are using ext2 on the CF instead of vfat, but it does work.
Seems to work for you?
Best regards,
Wolfgang Denk
On Feb 10, 2008 1:57 PM, Wolfgang Denk wd@denx.de wrote:
is not in the best of shape). That being said, we boot a
There is a number of MIPS board that are working pretty well - Andrew: what exactly do you mean by "not in the best of shape"?
AFAIK the current low level code is pretty specific to one processor - some Infineon chip used on one of the ports. It kinda works on a few others. There are a number of problems extending that to 'all MIPS' or even just MIPS32 compatible parts: cache init/cache handling, CP0 handling, hardcoded checks for denx toolchain, and probably a few others that I've forgotten.
That said, I mean no disrespect to Shinya and other maintainers, I think Shinya is doing a great job. We've discussed these issues, and it'll just take time and effort to clean up what's there. U-boot is the bootloader for PPC, but for MIPS many people use RedBoot or YAMON or CFE or pmon, depending on what their eval board came with, so it's a smaller user base.
Seems to work for you?
It does, but we started from a patch for the Au1500 that made it a lot easier. I think you also know I've submitted a fair number of bug fixes and patches for stuff along the way.
As far as getting the job done, since he has a platform that already suits most of his needs, it seems like adding basic ATA support and FAT support to that in C code would be easier than trying to work through the low-level issues with the u-boot MIPS code on a proc that is not supported. (Particularly if he doesn't have access to good debugging tools, or is not well versed in the low-level arch details)
participants (3)
-
Andrew Dyer -
Sean Parker -
Wolfgang Denk