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

[Russell Senior]

(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

 b) use an intermediate u-boot that looks for the kernel in a ubi partition.

or

 c) make the damn kernel smaller.

Thoughts?

-- 
Russell Senior
russell at personaltelco.net