Coreboot build process with gcc 8.1

[Salvatore Bellizzi]

      Hi,
I have a question reguarding the build process.

Since crossgcc has been updated and gcc is now at version 8.1 I always
encounter an error when building coreboot:

coreboot/src/console/vtxprintf.c:102: undefined reference to
'__udivmoddi4'

Since coreboot uses crossgcc and its own libgcc libraries, I figured
that the __udivmoddi4 function has not yet been implemented.

Anyway I have incurred in this failure several times and even with the
latest 4.9 release. Shouldn't I be able to build at least this latest
release using unmodified crossgcc or am I missing something else?

thanks,
salvatore

[Angel Pons]

      Hello Salvatore,

On Sat, Dec 29, 2018, 12:24 Salvatore Bellizzi <coreboot(a)seppia.net wrote:

  Hi,
 I have a question reguarding the build process.

 Since crossgcc has been updated and gcc is now at version 8.1 I always
 encounter an error when building coreboot:

 coreboot/src/console/vtxprintf.c:102: undefined reference to
 '__udivmoddi4'
If I remember properly, this happens when using the x86_64 (64-bit)
toolchain with coreboot for x86 mainboards, on which coreboot runs in
32-bit mode. The older x86_64 GCC6 toolchain had a multilib patch which
allowed it to compile to i386 (32-bit) machine code, which is why it worked
fine. However, the x86_64 GCC8 toolchain does not have the aforementioned
patch and fails.

Since coreboot uses crossgcc and its own libgcc libraries, I figured
  that the __udivmoddi4 function has not yet been
implemented.

 Anyway I have incurred in this failure several times and even with the
 latest 4.9 release. Shouldn't I be able to build at least this latest
 release using unmodified crossgcc or am I missing something else?

Definitely, you should be able to, but you need crossgcc-i386 to build
coreboot for x86 platforms.

thanks,
  salvatore
Best regards,

Angel Pons

[Salvatore Bellizzi]

      On Sat, 2018-12-29 at 12:38 +0100, Angel Pons wrote:
  Hello Salvatore,
 
 On Sat, Dec 29, 2018, 12:24 Salvatore Bellizzi <coreboot(a)seppia.net wrote:
 
  Hi,
 I have a question reguarding the build process.
 
 Since crossgcc has been updated and gcc is now at version 8.1 I always
 encounter an error when building coreboot:
 
 coreboot/src/console/vtxprintf.c:102: undefined reference to
 '__udivmoddi4'
 
 If I remember properly, this happens when using the x86_64 (64-bit)
 toolchain with coreboot for x86 mainboards, on which coreboot runs in
 32-bit mode. The older x86_64 GCC6 toolchain had a multilib patch which
 allowed it to compile to i386 (32-bit) machine code, which is why it worked
 fine. However, the x86_64 GCC8 toolchain does not have the aforementioned
 patch and fails.
That was it. I thought I didn't need the i386 toolchain since I was
building for an x86_64 board but I was evidently mistaken. After
building also the i386 GCC8 toolchain I was able to successfully build
coreboot 4.9 stable and from master branch too.

Thank you Angel,

Salvatore Bellizzi