Re: Changing kernel uncompressing address

[Matt Mackall <mpm@selenic.com>]

On Sun, Mar 21, 2004 at 11:52:07AM +0100, Alexander Simon wrote:
> Hi!
> 
> I have an old Toshiba Satellie Pro Laptop with broken RAM.
> I thought it could be no problem getting it to work with the BadRAM patch.
> But first RAM Errors occur at 2M and last until 32M
> Unfornately, the RAM Chips are on board, so no chance of replacing them.
> When I try to load a kernel image from diskette, it unpacks the kernel 
> image without errors. But when it tries to start that kernel it stops or 
> reboots.
> If I keep the kernel very very small, it starts, but I would have to 
> exclude TCP/IP code, causing the system unusable.
> 
> After studying arch/i386/boot/compressed/head.S and misc.c of 2.4.24 for 
> a long time, i found out that the kernel is uncompressed to 0x100000.
> Stupidly, I'm not familiar with assembler code. So I just changed the 
> 0x100000 to 0xF00000 (should be 16M?!? memtest86 reported the range 
> 15M-18M OK, however...) in line 77 in head.S and line 309 in misc.c.
> Of couse it did NOT work :[.
> I would need to high loaded kernel anyway, again because of TCP/IP.

That's part of it, you'll also need to tweak the boot-time page tables
and whatnot to cover all of the space you need.

-- 
Matt Mackall : http://www.selenic.com : Linux development and consulting