Failed to build goldfish kernel

[ysun]

Hi the guide is pretty cool. But I met a failure when I make kernel:

make O=out ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu x86_64_defconfig

make[1]: Entering directory '/data/kernel-android-emulator/goldfish/out'
  GEN     Makefile
#
# No change to .config
#
make[1]: Leaving directory '/data/kernel-android-emulator/goldfish/out'

make -j64 O=out ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu- CROSS_COMPILE=x86_64-linux-android-

root@chrome-server:/data/kernel-android-emulator/goldfish# make -j64 O=out  ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu- CROSS_COMPILE=x86_64-linux-android-
make[1]: Entering directory '/data/kernel-android-emulator/goldfish/out'
  GEN     Makefile
scripts/kconfig/conf  --syncconfig Kconfig
scripts/Kconfig.include:39:  gold linker 'x86_64-linux-android-ld' not supported
make[3]: *** [../scripts/kconfig/Makefile:73: syncconfig] Error 1
make[2]: *** [../Makefile:571: syncconfig] Error 2
make[1]: *** [/data/kernel-android-emulator/goldfish/Makefile:691: include/config/auto.conf.cmd] Error 2
make[1]: Leaving directory '/data/kernel-android-emulator/goldfish/out'
make: *** [Makefile:179: sub-make] Error 2
root@chrome-server:/data/kernel-android-emulator/goldfish#

I have not much experience on compiling Android or cross build kernel, so could you please guide me more ? Great thank.

Before the code change, I can cross build kernel 4.19 with gcc, but i have no idea how to do that with CLang.

Thanks
--Yi

[nathanchance]

You will need to use CROSS_COMPILE=x86_64-linux-androidkernel-

[ysun]

The same.
It seems we need lots of environment setting for CLang.
I's now using the whole Android compiling environment to build a kernel.

[nathanchance]

You should not be getting that exact same error? x86_64-linux-androidkernel-ld explicitly points to ld.bfd.

[ysun]

Thanks nathanchance for your quick response.
I re-ran the building as following:
Indeed, I got a different failure.
my repo: https://android.googlesource.com/kernel/goldfish/
branch: "android-5.4"

$ make O=out ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu  x86_64_defconfig
make[1]: Entering directory '/data/kernel-android-emulator/goldfish/out'
  GEN     Makefile
#
# configuration written to .config
#
make[1]: Leaving directory '/data/kernel-android-emulator/goldfish/out'

$ make O=out  ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu- CROSS_COMPILE=x86_64-linux-androidkernel-
make[1]: Entering directory '/data/kernel-android-emulator/goldfish/out'
  GEN     Makefile
  HOSTCC  arch/x86/tools/relocs_32.o
  HOSTCC  arch/x86/tools/relocs_64.o
  HOSTCC  arch/x86/tools/relocs_common.o
  HOSTLD  arch/x86/tools/relocs
  HOSTCC  scripts/selinux/genheaders/genheaders
  HOSTCC  scripts/selinux/mdp/mdp
  HOSTCC  scripts/kallsyms
  HOSTCC  scripts/pnmtologo
  HOSTCC  scripts/conmakehash
  HOSTCC  scripts/sortextable
  HOSTCC  scripts/asn1_compiler
  HOSTCC  scripts/extract-cert
  WRAP    arch/x86/include/generated/asm/dma-contiguous.h
  WRAP    arch/x86/include/generated/asm/early_ioremap.h
  WRAP    arch/x86/include/generated/asm/export.h
  WRAP    arch/x86/include/generated/asm/mcs_spinlock.h
  WRAP    arch/x86/include/generated/asm/mm-arch-hooks.h
  WRAP    arch/x86/include/generated/asm/mmiowb.h
Compiler lacks asm-goto support.
make[1]: *** [arch/x86/Makefile:308: checkbin] Error 1
make[1]: Leaving directory '/data/kernel-android-emulator/goldfish/out'
make: *** [Makefile:179: sub-make] Error 2

[nathanchance]

What version of clang are you using? asm goto support was added to clang-9 so it must be rather old.

[ysun]

$ clang --version
Android (5484270 based on r353983c) clang version 9.0.3 (https://android.googlesource.com/toolchain/clang 745b335211bb9eadfa6aa6301f84715cee4b37c5) (https://android.googlesource.com/toolchain/llvm 60cf23e54e46c807513f7a36d0a7b777920b5881) (based on LLVM 9.0.3svn)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /data/goldfish-kernel-54/prebuilts-master/clang/host/linux-x86/clang-r353983c/bin

[nathanchance]

I would use clang-r377782c, that appears to be what upstream goldfish uses: https://android.googlesource.com/kernel/goldfish/+/refs/heads/android-5.4/build.config.common#8

[ysun]

Cool, clang-r377782c works~! But there is still some issue.

$ make O=out ARCH=x86_64 CC=clang CLANG_TRIPLE=x86_64-linux-gnu- CROSS_COMPILE=x86_64-linux-androidkernel-

  AR      arch/x86/lib/built-in.a
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  AR      init/built-in.a
  LD      vmlinux.o
  MODPOST vmlinux.o
  MODINFO modules.builtin.modinfo
  LD      .tmp_vmlinux1
  KSYM    .tmp_kallsyms1.o
  LD      .tmp_vmlinux2
  KSYM    .tmp_kallsyms2.o
  LD      vmlinux
  SORTEX  vmlinux
  SYSMAP  System.map
  LDS     arch/x86/boot/compressed/vmlinux.lds
  AS      arch/x86/boot/compressed/head_64.o
  VOFFSET arch/x86/boot/compressed/../voffset.h
  CC      arch/x86/boot/compressed/misc.o
  CC      arch/x86/boot/compressed/cmdline.o
  CC      arch/x86/boot/compressed/error.o
  OBJCOPY arch/x86/boot/compressed/vmlinux.bin
  RELOCS  arch/x86/boot/compressed/vmlinux.relocs
Invalid absolute R_X86_64_32S relocation: _etext
make[3]: *** [../arch/x86/boot/compressed/Makefile:130: arch/x86/boot/compressed/vmlinux.relocs] Error 1
make[3]: *** Deleting file 'arch/x86/boot/compressed/vmlinux.relocs'
make[2]: *** [../arch/x86/boot/Makefile:112: arch/x86/boot/compressed/vmlinux] Error 2
make[1]: *** [arch/x86/Makefile:289: bzImage] Error 2
make[1]: Leaving directory '/data/kernel-android-emulator/goldfish/out'
make: *** [Makefile:179: sub-make] Error 2

[nathanchance]

You should probably add LD=ld.lld to your make command.

[ysun]

Yes, awesome! By add LD=ld.ldd, I can compile Android kernel now.
BTW, do you know how to replace 5.4 kernel in Android emulator? Must I repackage system image?

[nathanchance]

No. Honestly, if you care about hacking up the kernel on a virtual Android platform, you should take a look at Cuttlefish.

https://source.android.com/setup/create/cuttlefish

https://nathanchance.dev/posts/building-using-cuttlefish/

[hongwen000]

@nathanchance Cuttlefish sucks, never worked normally like any Google "new" things.