byhoo [off-list ref] writes:

The steps:
1. add "#define DEBUG" in
drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c line 61.
2. make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- O=../Out_Linux
bcm2835_defconfig
3. make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- O=../Out_Linux/
zImage modules dtbs -j8

Then, it will fail, the compile log described below:

Kernel: arch/arm/boot/zImage is ready MODPOST Module.symvers ERROR:
modpost: "brcmf_debugfs_add_entry"
[drivers/net/wireless/broadcom/brcm80211/brcmfmac/brcmfmac.ko]
undefined! ERROR: modpost: "brcmf_debugfs_get_devdir"
[drivers/net/wireless/broadcom/brcm80211/brcmfmac/brcmfmac.ko]
undefined! ERROR: modpost: "__brcmf_dbg"
[drivers/net/wireless/broadcom/brcm80211/brcmfmac/brcmfmac.ko]
undefined!
/home/hby/gitee/linux_origin/Linux/scripts/Makefile.modpost:111:
recipe for target 'Module.symvers' failed make[2]: ***
[Module.symvers] Error 1 make[2]: *** Deleting file 'Module.symvers'
/home/hby/gitee/linux_origin/Linux/Makefile:1390: recipe for target
'modules' failed make[1]: *** [modules] Error 2 make[1]: Leaving
directory '/home/hby/gitee/linux_origin/Out_Linux' Makefile:185:
recipe for target '__sub-make' failed make: *** [__sub-make] Error 2 

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