How can I support 2GB of memory in Linux kernel on 440SPe

3 messages, 2 authors, 2007-12-30 · open the first message on its own page

How can I support 2GB of memory in Linux kernel on 440SPe

From: Vincitore <hidden>
Date: 2007-12-28 13:59:42

Hi,

I need to support 2GB of memory on a custom 440SPe board.

I see to support 1GB of memory on the 440SPe yucca board the following
configuration changes were done.

#
# Advanced setup
#

CONFIG_ADVANCED_OPTIONS=y
CONFIG_HIGHMEM_START=0xfe000000
CONFIG_LOWMEM_SIZE_BOOL=y
CONFIG_LOWMEM_SIZE=0x40000000
CONFIG_KERNEL_START_BOOL=y
CONFIG_KERNEL_START=0xa0000000
# CONFIG_TASK_SIZE_BOOL is not set
CONFIG_TASK_SIZE=0x80000000
# CONFIG_CONSISTENT_START_BOOL is not set CONFIG_CONSISTENT_START=0xff100000
# CONFIG_CONSISTENT_SIZE_BOOL is not set
CONFIG_CONSISTENT_SIZE=0x00200000 # CONFIG_BOOT_LOAD_BOOL is not set
CONFIG_BOOT_LOAD=0x01000000

It looks like the only thing I would need to do is modify the
following for 2GB support.

CONFIG_LOWMEM_SIZE=0x80000000
and
CONFIG_KERNEL_START=0x60000000

But this does not work. It almost does, but right after I get to the
Linux prompt, this system panics. If I scale back to one 1GB
everything works great.

Any ideas?

Thank You,

Vincitore

RE: How can I support 2GB of memory in Linux kernel on 440SPe

From: Rune Torgersen <hidden>
Date: 2007-12-28 15:35:55

From: linuxppc-embedded-bounces+runet=3Dinnovsys.com@ozlabs.org=20
[mailto:linuxppc-embedded-bounces+runet=3Dinnovsys.com@ozlabs.or
g] On Behalf Of Vincitore
Sent: Friday, December 28, 2007 8:00 AM
To: linuxppc-embedded@ozlabs.org
Subject: How can I support 2GB of memory in Linux kernel on 440SPe
=20
Hi,
=20
I need to support 2GB of memory on a custom 440SPe board.
=20
I see to support 1GB of memory on the 440SPe yucca board the following
configuration changes were done.
Just leave the configuration for 1 GB, and enable CONFIG_HIGHMEM
That gives you 2 (or more) GB of RAM, with 1G as lowmwm.

Re: How can I support 2GB of memory in Linux kernel on 440SPe

From: Vincitore <hidden>
Date: 2007-12-30 15:31:03

Hi Rune,

I tried what you suggested. With no luck.

I enabled CONFIG_HIGHMEM=y

Now I panic when  when unpacking_rootfs.

...
Memory: 2076148k available (2160k kernel code, 764k data, 144k init,
1048572k highmem)
Mount-cache hash table entries: 512
checking if image is initramfs...Oops: kernel access of bad area, sig: 11 [#1]
NIP: A02A9618 LR: A02A9598 CTR: A002EAE8
REGS: dfc01e60 TRAP: 0300   Not tainted  (2.6.19.2)
MSR: 00029000 <EE,ME>  CR: 24000084  XER: 00000000
DAR: 1FDEA000, DSISR: 00000000
TASK = a13e4ba0[1] 'swapper' THREAD: dfc00000
GPR00: 00000000 DFC01F10 A13E4BA0 DFC10000 000000D0 00000001 2D89B700 A02C0000
GPR08: DFC01D18 A02C0000 00000000 A02C3F78 24000084 70000000 A02D0000 00000000
GPR16: 00000001 00800000 7FFFF0FC 00000000 A02C0000 A02C0000 7FFEE61C 00000001
GPR24: 00000000 007FFE70 00000D80 00184F9D 1FDEA000 A02D0000 A00012F8 A02D0000
NIP [A02A9618] unpack_to_rootfs+0xdc/0xa54
LR [A02A9598] unpack_to_rootfs+0x5c/0xa54
Call Trace:
[DFC01F10] [A02A9598] unpack_to_rootfs+0x5c/0xa54 (unreliable)
[DFC01F60] [A02AA050] populate_rootfs+0x7c/0x104
[DFC01F80] [A0001328] init+0x30/0x2a4
[DFC01FF0] [A00047E0] kernel_thread+0x44/0x60
Instruction dump:
912b0000 3ce0a02c 3d20a02c 914b0004 90074038 90093f8c 3ce0a02c 80074038
2f800000 409e0054 2f9b0000 419e004c <881c0000> 39753f78 2f800030 82cb0000

This is the same if I have CONFIG_HIGHMEM disabled. The only
difference is highmem now shows up as 0k.

Memory: 2076148k available (2160k kernel code, 764k data, 144k init, 0k highmem)
Mount-cache hash table entries: 512
checking if image is initramfs...Oops: kernel access of bad area, sig: 11 [#1]
...


Vincitore

On 12/28/07, Rune Torgersen [off-list ref] wrote:
quoted
From: linuxppc-embedded-bounces+runet=innovsys.com@ozlabs.org
[mailto:linuxppc-embedded-bounces+runet=innovsys.com@ozlabs.or
g] On Behalf Of Vincitore
Sent: Friday, December 28, 2007 8:00 AM
To: linuxppc-embedded@ozlabs.org
Subject: How can I support 2GB of memory in Linux kernel on 440SPe

Hi,

I need to support 2GB of memory on a custom 440SPe board.

I see to support 1GB of memory on the 440SPe yucca board the following
configuration changes were done.
Just leave the configuration for 1 GB, and enable CONFIG_HIGHMEM
That gives you 2 (or more) GB of RAM, with 1G as lowmwm.
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