From: Magnus Hjorth <mh@omnisys.se>
To: manu <manuel.pezzin@free.fr>
Cc: Linuxppc-embedded@ozlabs.org
Subject: Re: problems to boot 2.6.23 kernel on XILINX ppc with 8Mbytes of RAM
Date: Thu, 25 Oct 2007 09:00:09 +0200 [thread overview]
Message-ID: <47203EF9.1070906@omnisys.se> (raw)
In-Reply-To: <471FA48B.2020809@free.fr>
[-- Attachment #1: Type: text/plain, Size: 1504 bytes --]
Hello Manu,
Could you try the attached patch to arch/ppc/mm/4xx_mmu.c and see if it
solves your problem?
Best regards,
Magnus
manu wrote:
> Hello,
> I work on a custom board based on a virtex 2 pro FPGA and 8Mbytes of SDRAM.
> Untill now I used a 2.4.31 linux ppc kernel with John Williams patches
> and uclinux distribution and everything worked perfectly.
> I've decided to move to the latest 2.6 version from kernel.org
> (2.6.23.1) with an initramfs containing a busybox.
> My complete zImage including the initramfs has a size of 900Kbytes.
> I made some tests with a ML300 board and I managed to get a shell easily.
> When I migrated to the custom board, I had the "Now booting the kernel"
> message and then nothing.
> When I trace the code running on the ppc with the debugger, execution
> seems to be stuck in some early initialization code.
> I managed to reproduce the problem on the ML300 using "mem=8m" parameter
> on the bootline.
> With "mem=16m" the kernel boots correctly.
> I'm really surprised by the amount of RAM required to boot the kernel.
> Is there a way to make it boot with only 8Mbytes of RAM ?
> Thanks for your help.
>
> Manu
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
--
Magnus Hjorth, M.Sc.
Omnisys Instruments AB
Gruvgatan 8
SE-421 30 Västra Frölunda, SWEDEN
Phone: +46 31 734 34 09
Fax: +46 31 734 34 29
http://www.omnisys.se
[-- Attachment #2: 4xx_mmu.patch --]
[-- Type: text/plain, Size: 589 bytes --]
--- 4xx_mmu_old.c 2007-10-25 08:54:46.000000000 +0200
+++ 4xx_mmu.c 2007-10-25 08:55:57.000000000 +0200
@@ -105,7 +105,7 @@
return s;
}
- while (s <= (total_lowmem - LARGE_PAGE_SIZE_16M)) {
+ while (s + LARGE_PAGE_SIZE_16M <= total_lowmem) {
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_16M | _PAGE_HWEXEC | _PAGE_HWWRITE;
@@ -120,7 +120,7 @@
s += LARGE_PAGE_SIZE_16M;
}
- while (s <= (total_lowmem - LARGE_PAGE_SIZE_4M)) {
+ while (s + LARGE_PAGE_SIZE_4M <= total_lowmem) {
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_4M | _PAGE_HWEXEC | _PAGE_HWWRITE;
next prev parent reply other threads:[~2007-10-25 7:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-24 20:01 problems to boot 2.6.23 kernel on XILINX ppc with 8Mbytes of RAM manu
2007-10-25 7:00 ` Magnus Hjorth [this message]
2007-10-26 18:43 ` manu
2007-10-26 19:54 ` Grant Likely
2007-10-27 8:35 ` [PATCH] ppc4xx: mmu_mapin_ram bugfix for booting with mem<16 MB Magnus Hjorth
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