U-BOOT !!!!!!!!!!!!

Hi MFM,

Ok, so I finally had a chance to review the buildroot scripts, etc. Here's what I believe is

going on:

1. First, there are two elf files created. This is not unusual -- one is the kernel elf vmlinux.

The other is the compressed kernel elf (zImage). The zImage is in the boot/compressed tree.

2. **Important** -- the zImage head.S is _not_, repeat _not_ coded to relocate itself. So you

__MUST__ use the exact load address for this -- or add the relocation code.

3. The .text VMA of the zImage defaults to 0080_0000 above the .text VMA for the vmlinux.

You can change this with the BOOT_LINK_OFFSET configuration option.

So, here's what you have to do:

1. Use the zImage (the elf from the boot/compressed tree) and create a binary. The binary should

be passed to mkimage with compression 'none' and the load and entry point addresses 0080_0000 above your ram base. In your case this should be 0180_0000. mkimage would look

like:

$ mkimage -C none -e 0x01800000 -a 0x01800000 -d zImage.bin <<other parameters>>

2. Use the vmlinux (not from the boot/compressed tree) and create a binary. Compress the binary

(e.g. vmlinux.bin.gz). Pass the compressed binary to mkimage with compression &#39;gzip&#39;. Set the

load and entry point addresses to some valid address in ram (the kernel can relocate itself).

But since u-boot will be decompressing, you might as well set the load/entry addresses to

the actual VMA: 0x0100_0000:

$ mkimage -C gzip -e 0x01000000 -a 0x01000000 -d vmlinux.bin.gz <<other parameters>>

================================================================

Just to review, so everyone knows where the problem is:

The zImage does _not_ relocate itself. Setting the load/entry address to anything other

than the correct VMA will cause the zImage to jump into the weeds. And, there&#39;s no

need to compress a zImage -- it&#39;s already compressed -- so don&#39;t tell u-boot that it is.

You can satisfy yourself that this is the case: use nios2-console, but load the binary

to address 0x018000000 and it should work.

Regards,

--Scott