Dear Scott,
in message <43EB80E07C42E1408726E4905FB96B0466C6C0 at CYBORG3.cyclone.com> you
wrote:
>
> I am not sure if this is a linux question or a u-boot question. I have
> a custom MPC8540 board running U-boot 1.1.4. With a NFS root
> configuration, I have booted and run 2.6.15 with memory from 256MB to
> 2GB. If I build a ramdisk image (or even if I use the ramdisk image
> with the 85xx version of ELDK 4.0) and then combine it with the kernel
> image (vmlinux.gz) using "mkimage", the linux boot blows out with an
> oops if I boot the board with more that 512MB of DRAM. From the U-boot
Do you see something like
mem_pieces_remove: [3fe32000,3ff93ec7) not in any region
in your boot messages?
> output, it looks like the ramdisk image is getting copied to the upper
> portion of DRAM. Is it possible that the kernel doesn't map enough DRAM
> to allow the image to be read?
>
> I haven't spent a lot of time debugging this once I saw that the 512MB
> configuration worked OK. Has anyone run into this?
Yes. Normally you can use only use 0x30000000 (768MB) RAM (lowmem);
if you need more you have to change your kernel configuration,
including shifting the kernel start address.
For example, on on a 1 GB system something like this could work:
CONFIG_ADVANCED_OPTIONS=y
CONFIG_LOWMEM_SIZE_BOOL=y
CONFIG_LOWMEM_SIZE=0x40000000
CONFIG_KERNEL_START_BOOL=y
CONFIG_KERNEL_START=0xa0000000
# CONFIG_CONSISTENT_START_BOOL is not set
# CONFIG_CONSISTENT_SIZE_BOOL is not set
# CONFIG_BOOT_LOAD_BOOL is not set
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Disobedience: The silver lining to the cloud of servitude.
- Ambrose Bierce
