Re: kernel args from u-boot on M5282LITE

On Feb 11, 2008, at 2:20 AM, Greg Ungerer wrote:

> 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?

Well no. That's why I stash the pointer right after the disabling of  
interrupts; I think it's the 3rd assembly instruction into the kernel...

I had a patch for the 2.6.19-uc1 kernel; Now that I'm on 2.6.24-uc0,  
I'll apply it there and send out patches. The code has been cleaned  
up a bit between releases. (okay patches - still waiting for a  
release ;) ;);) )
-
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.