BUG: as of 2967e24d0 "ramips: switch to Linux 6.6' ERX kernel is too big

[Tim Lunn]

Hi Russel,

On 5/20/24 11:50, Russell Senior wrote:
> (try#2, damn you gmail)
>
> I mentioned this on IRC and as a github comment on the commit
> (https://github.com/openwrt/openwrt/commit/2967e24d02775f63d9e363e6e0d351716dcc3f7c)
>
> My build started failing on the commit. The message I get from the
> build system is:
>
>    "WARNING: Image file
> /home/openwrt/src/lede/build_dir/target-mipsel_24kc_musl/linux-ramips_mt7621/ubnt_edgerouter-x-kernel.bin
> is too big: 3165615 > 3145728"
>
> I tried a vanilla config:
>
>    CONFIG_TARGET_ramips=y
>    CONFIG_TARGET_ramips_mt7621=y
>    CONFIG_TARGET_ramips_mt7621_DEVICE_ubnt_edgerouter-x=y
>    CONFIG_DEVEL=y
>    CONFIG_BUILD_LOG=y
>
>    "WARNING: Image file
> /home/openwrt/src/lede/build_dir/target-mipsel_24kc_musl/linux-ramips_mt7621/ubnt_edgerouter-x-kernel.bin
> is too big: 3165361 > 3145728"
>
> I notice that there are two kernel partitions on the NAND flash, each
> of which is 3MB:
>
> [    1.011604] 6 fixed-partitions partitions found on MTD device mt7621-nand
> [    1.025136] Creating 6 MTD partitions on "mt7621-nand":
> [    1.035552] 0x000000000000-0x000000080000 : "u-boot"
> [    1.054525] 0x000000080000-0x0000000e0000 : "u-boot-env"
> [    1.072180] 0x0000000e0000-0x000000140000 : "factory"
> [    1.089606] 0x000000140000-0x000000440000 : "kernel1"
> [    1.147424] 0x000000440000-0x000000740000 : "kernel2"
> [    1.204979] 0x000000740000-0x00000ff00000 : "ubi"
>
> Which suggests two possible fixes:
>
>   a) cannibalize the second kernel parition (might require a different
> u-boot?); or
I have an open PR that resolves this by merging the 2 kernel partitions.
https://github.com/openwrt/openwrt/pull/15194

I created this before the switch to 6.6 as default in anticipation of 
the breakage caused here, and also to fix snapshot builds. So far it has 
two approving reviews,  however at this point I am not to sure what else 
needs to be done to get this merged. It would however be nice to see 
this resolved and the return of snapshots.

Regards
   Tim
>
>   b) use an intermediate u-boot that looks for the kernel in a ubi partition.
>
> or
>
>   c) make the damn kernel smaller.
>
> Thoughts?
>