Chromium version 53 for ARM gn build issue

Question

I have a problem when building chromium for ARM platform. Here are some details about my host server:

Linux version 4.2.0-42-generic (buildd@lgw01-55) (gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.3) )

And I use Chromium version 53.0.2785.143. I tried to use gn to build the chromium, and here is my arguments in args.gn file:

target_cpu = "arm"
arm_tune = "generic-armv7-a"
arm_float_abi = "softfp"

Basically, I used these specific arguments above because of my ARM platform. And the gn command ran without errors. However, when building project with ninja, the following errors popped out:

ninja: Entering directory `out/Default_arm64' [1/1] Regenerating ninja files [296/46119] LINK ./minidump-2-core FAILED: minidump-2-core ../../third_party/llvm-build/Release+Asserts/bin/clang++ -Wl,--fatal-warnings -fPIC -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -Wl,-z,defs -fuse-ld=gold -B../../third_party/binutils/Linux_x64/Release/bin -Wl,--icf=all -pthread --target=arm-linux-gnueabihf --sysroot=../../build/linux/debian_wheezy_arm-sysroot -L/home/miaozixiong/workspace/chromium/src/build/linux/debian_wheezy_arm-sysroot/lib/arm-linux-gnueabihf -Wl,-rpath-link=/home/miaozixiong/workspace/chromium/src/build/linux/debian_wheezy_arm-sysroot/lib/arm-linux-gnueabihf -L/home/miaozixiong/workspace/chromium/src/build/linux/debian_wheezy_arm-sysroot/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link=/home/miaozixiong/workspace/chromium/src/build/linux/debian_wheezy_arm-sysroot/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link=../Default_arm64 -Wl,--disable-new-dtags -o "./minidump-2-core" -Wl,--start-group @"./minidump-2-core.rsp" -Wl,--end-group -ldl -lrt ld.gold: error: obj/breakpad/minidump-2-core/minidump-2-core.o uses VFP register arguments, output does not

...

I am new to chromium and have no clue about what do those errors mean. So anybody knows how to work around? You are appreciated.

Note: I need my arm_float_abi attribute to be "softfp" according to my ARM platform. So please note I cannot change it to "hard". Also, when set float abi = "hard", there is no building errors.

valiano valiano · Accepted Answer · 2017-07-15T15:58:34

ld.gold: error: obj/breakpad/minidump-2-core/minidump-2-core.o uses VFP register arguments, output does not

This a linking error to indicate that minidump-2-core cannot be linked, due to a mismatch in the floating point ABI: the object minidump-2-core.o is compiled for hard floats (the generated code takes advantage of the ARM VFP unit - "uses VFP register arguments"), but the target executable is requested to use soft floats (in which floating point support is emulated, rather than using specialized FP hardware instructions).

According to this bug report, Chromium should build fine with soft float.

My best guess is, try replacing softfp by just soft: arm_float_abi = "soft". According to gcc documentation, softfp maintains the soft ABI but still 'allows the generation of code using hardware floating-point instructions', which could lead to the seen error.

If that won't work, you might want to check this tutorial on cross building Chromium for ARM:
https://unix.stackexchange.com/questions/176794/how-do-i-cross-compile-chromium-for-arm

Chromium version 53 for ARM gn build issue

2 Answers