On Tue, Nov 20, 2012 at 10:45 PM, Solomon Peachy [off-list ref] wrote:

When compiling the firmware loader, the builtin firmware functions were
erroneously compiled as they were wrapped with CONFIG_FW_LOADER instead
of CONFIG_FIRMWARE_IN_KERNEL.  This is normally harmless, except when
there was actually no firmware to compile into the kernel, causing the
build to fail with a linking error:

drivers/built-in.o: In function `release_firmware':
(.text+0x192e2): undefined reference to `__end_builtin_fw'
drivers/built-in.o: In function `release_firmware':
(.text+0x19304): undefined reference to `__end_builtin_fw'
drivers/built-in.o: In function `_request_firmware':
firmware_class.c:(.text+0x1986c): undefined reference to `__end_builtin_fw'
firmware_class.c:(.text+0x19886): undefined reference to `__end_builtin_fw'
firmware_class.c:(.text+0x19a98): undefined reference to `__end_builtin_fw'
drivers/built-in.o: In function `release_firmware':
(.text+0x192dc): undefined reference to `__start_builtin_fw'
drivers/built-in.o: In function `_request_firmware':
firmware_class.c:(.text+0x19860): undefined reference to `__start_builtin_fw'
firmware_class.c:(.text+0x19a8a): undefined reference to `__start_builtin_fw'

I have tried to reproduce the compile failure but not succeed, could you share
your .config?

This might not be correct when EXTRA_FIRMWARE is set and
CONFIG_FIRMWARE_IN_KERNEL is unset.

Thanks,
-- 
Ming Lei