travis: Add some arm builds #698

1. 
   MarcoFalke commented at 8:47 pm on December 5, 2019: none

   Proof of concept for #598

   Not sure which environment combinations make most sense (something with ASM?)

2. 
   sipa commented at 8:57 pm on December 5, 2019: contributor

   We have optimized assembly for 32-bit ARM (not enabled by default, and not 64-bit iirc). It’d be neat to test that.
3. 
   MarcoFalke commented at 9:15 pm on December 5, 2019: none

   ok, I set ASM=arm, but that fails:

    0$ if [ -n "$BUILD" ]; then make -j2 $BUILD; fi
    1
    2  CC       src/bench_verify.o
    3
    4  CC       src/bench_sign.o
    5
    6  CC       src/exhaustive_tests-tests_exhaustive.o
    7
    8gcc -I. -I./src -g -O2 -Wall -Wextra -Wno-unused-function -c src/gen_context.c -o gen_context.o
    9
   10  CCAS     src/asm/field_10x26_arm.lo
   11
   12src/asm/field_10x26_arm.s: Assembler messages:
   13
   14src/asm/field_10x26_arm.s:1: Error: junk at end of line, first unrecognized character is `@'
   15
   16src/asm/field_10x26_arm.s:18: Error: unknown pseudo-op: `.syntax'
   17
   18src/asm/field_10x26_arm.s:19: Error: junk at end of line, first unrecognized character is `@'
   19
   20src/asm/field_10x26_arm.s:20: Error: unknown pseudo-op: `.eabi_attribute'
   21
   22src/asm/field_10x26_arm.s:21: Error: unknown pseudo-op: `.eabi_attribute'
   23
   24src/asm/field_10x26_arm.s:24: Error: junk at end of line, first unrecognized character is `@'
   25
   26src/asm/field_10x26_arm.s:27: Error: junk at end of line, first unrecognized character is `@'
   27...
   

   See https://travis-ci.org/MarcoFalke/secp256k1/builds/621315153

4. 
   elichai commented at 9:16 pm on December 5, 2019: contributor

   Tried that in the past and couldn’t make the asm work. Hope you will :)
5. 
   real-or-random commented at 11:41 pm on December 5, 2019: contributor

   I haven’t had a closer look now but this may help to figure out the right flags (even though it’s for cross-compilation) #621 (comment)
6. 
   laanwj commented at 7:29 am on December 6, 2019: member

   I think you get those errors when trying to compile the 32-bit ARM assembly with a 64-bit targeted assembler.
7. 
   MarcoFalke commented at 9:24 pm on December 9, 2019: none

   I might need to install libc from armhf. That doesn’t work, so I reported the issue to travis: https://travis-ci.community/t/apt-addon-does-not-work-for-armhf-on-arm64/6374
8. travis: Add some arm builds 15ee50a365
9. MarcoFalke closed this on Dec 12, 2019

   ---

10. 
    real-or-random commented at 7:27 pm on December 12, 2019: contributor

    Did this work in the end? The travis output looks good, it was just aborted?
11. 
    MarcoFalke commented at 7:39 pm on December 12, 2019: none

    It failed with

    0/usr/lib/gcc-cross/arm-linux-gnueabihf/5/../../../../arm-linux-gnueabihf/bin/ld: cannot find crti.o: No such file or directory
    

    https://travis-ci.org/MarcoFalke/secp256k1/jobs/624276878#L396

12. 
    real-or-random commented at 9:50 pm on December 12, 2019: contributor

    Ah yes, thanks for clarifying!
13. MarcoFalke deleted the branch on Nov 9, 2021

Contributors
MarcoFalke sipa elichai real-or-random laanwj