Re: kernel args from u-boot on M5282LITE
Greg Ungerer <[email protected]>
| Newsgroups | gmane.comp.hardware.motorola.microcontrollers.coldfire |
|---|---|
| Message-ID | <[email protected]> |
Hi Allon, Allon Stern wrote: > So, I figured out a way to pass kernel arguments from u-boot on the > M5282LITE. U-Boot calls the kernel, passing arguments on the stack; all > that is needed is to stash the pointer to the arguments (stashed in high > mem) when the kernel first starts, and before the stack pointer is > trounced, then use that pointer slightly later when the arguments are > looked at. > > Any comments on this hack? Should I expect it to fail, and be surprised > that it works? The thing to watch is where in practice do the args end up being in the memory map? The linux kernel will do a fair bit of setup (clear bss, initial allocations, etc) before it gets around to looking at the args. Will they have been overwritten by this time? > Also, I'm somewhat puzzled that the stack pointer appears to be offset a > bit from where I would expect it to be, looking at the disassembly. I > don't have a BDM interface just yet, so I can't debug it to that level..... > > If there is interest, I can post a patch for the 2.6.19-uc1 kernel; if I > manage to get the later kernel actually working, I'll put it in there > too. I'd really like to get the SP offset figured out, though it's > working and I don't want to complain too much :) Please do post patches. Regards Greg > Also, how can one write to the internal flash from from u-boot? Is there > an easy patch to a current u-boot? > - > allon > > > --- > [email protected] Send a post to the list. > [email protected] Join the list. > [email protected] Join the list in digest mode. > [email protected] Leave the list. > > -- ------------------------------------------------------------------------ Greg Ungerer -- Chief Software Dude EMAIL: [email protected] Secure Computing Corporation PHONE: +61 7 3435 2888 825 Stanley St, FAX: +61 7 3891 3630 Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com --- [email protected] Send a post to the list. [email protected] Join the list. [email protected] Join the list in digest mode. [email protected] Leave the list.