What should I do with busybox image running on MIPS platform?

[docker-library]

What should I do with busybox image running on MIPS platform?

[tianon]

I think the first hurdle is hardware availability: docker-library/official-images#6709

We're working with @wanghuaiqing2010 to resolve that, but it's somewhat entangled (from a legal perspective).

With hardware available, the challenge from the perspective of this repository will be getting some of the */Dockerfile.builder images building successfully on the MIPS platform (which will require alpine and/or debian images available).

[tianon]

When configuring Buildroot to target uClibc for mips64le, is anything besides BR2_mips64el=y necessary? For example, do we need to specify a particular instruction variant?

See our 32bit ARM variants for an example of what I mean:

busybox/uclibc/Dockerfile.builder

Lines 80 to 108 in 49ea4fe

	# https://wiki.debian.org/ArmEabiPort#Choice_of_minimum_CPU
	# https://github.com/free-electrons/toolchains-builder/blob/db259641eaf5bbcf13f4a3c5003e5436e806770c/configs/arch/armv5-eabi.config
	# https://git.busybox.net/buildroot/tree/arch/Config.in.arm
	# (Debian minimums at ARMv4, we minimum at ARMv5 instead)
	armel) \
	setConfs="$setConfs \
	BR2_arm=y \
	BR2_arm926t=y \
	BR2_ARM_EABI=y \
	BR2_ARM_INSTRUCTIONS_THUMB=y \
	BR2_ARM_SOFT_FLOAT=y \
	"; \
	;; \
	\
	# "Currently the Debian armhf port requires at least an ARMv7 CPU with Thumb-2 and VFP3D16."
	# https://wiki.debian.org/ArmHardFloatPort#Supported_devices
	# https://github.com/free-electrons/toolchains-builder/blob/db259641eaf5bbcf13f4a3c5003e5436e806770c/configs/arch/armv7-eabihf.config
	# https://git.busybox.net/buildroot/tree/arch/Config.in.arm
	armhf) \
	setConfs="$setConfs \
	BR2_arm=y \
	BR2_cortex_a9=y \
	BR2_ARM_EABIHF=y \
	BR2_ARM_ENABLE_VFP=y \
	BR2_ARM_FPU_VFPV3D16=y \
	BR2_ARM_INSTRUCTIONS_THUMB2=y \
	"; \
	unsetConfs="$unsetConfs BR2_ARM_SOFT_FLOAT"; \
	;; \

Some potential examples:

Target Architecture Variant
> 1. Generic MIPS64 (BR2_mips_64) (NEW)
  2. Generic MIPS64R2 (BR2_mips_64r2) (NEW)
  3. Generic MIPS64R3 (BR2_mips_64r3) (NEW)
  4. Generic MIPS64R5 (BR2_mips_64r5) (NEW)
  5. Generic MIPS64R6 (BR2_mips_64r6) (NEW)
  6. I6400 (BR2_mips_i6400) (NEW)
  7. Octeon II (BR2_mips_octeon2) (NEW)
  8. Octeon III (BR2_mips_octeon3) (NEW)
  9. P6600 (BR2_mips_p6600) (NEW)

Target ABI
> 1. n32 (BR2_MIPS_NABI32) (NEW)
  2. n64 (BR2_MIPS_NABI64) (NEW)

Use soft-float (BR2_MIPS_SOFT_FLOAT) [Y/n/?]

[tianon]

If we're matching how Debian defines mips64el ("The 'mips64el' port is a 64-bit little endian port using the N64 ABI, hardware floating point and the MIPS64R2 ISA." from https://wiki.debian.org/MIPSPort), we probably want BR2_mips_64r2=y, BR2_MIPS_NABI64=y, and BR2_MIPS_SOFT_FLOAT=n.