Re: [Buildroot] [PATCH 4/5] arch: drop support for SH2A

["Yann E. MORIN" <yann.morin.1998@free.fr>]

Thomas, All,

On 2022-04-19 23:34 +0200, Thomas Petazzoni via buildroot spake thusly:
> Until commit "arch/Config.in.sh: fixup MMU selection" in this series,
> SH2A could either be used with BR2_USE_MMU disabled or BR2_USE_MMU
> enabled.
> 
> The later made absolutely no sense, since SH2A does not have a MMU:
> MMU support was introduced starting from SH3 according to
> https://en.wikipedia.org/wiki/SuperH#SH-3
> 
> Also, since commit 22d5501e03b019218b718b5de7ca74824a8eaf42 ("arch:
> tidy up binary formats config"), which was merged in Buildroot
> 2015.05, the architecture tuple used when BR2_sh2a=y and BR2_USE_MMU
> disabled is sh2a-buildroot-uclinux-uclibc, and this was already
> unsupported back in the days of Buildroot 2015.08 and binutils 2.24,
> causing the build to fail with:
> 
> *** BFD does not support target sh2a-buildroot-uclinux-uclibc.
> 
> just like it fails to build today with recent version of binutils.
> 
> So, this has been broken since 2015.08, and nobody complained. SH2A is
> seldomly used, so it's time to kill.

seldomly is archaic [0]; seldom is an adverb [1]. ;-)
[0] https://www.merriam-webster.com/dictionary/seldomly
[1] https://www.merriam-webster.com/dictionary/seldom

Applied to master, thanks.

Regards,
Yann E. MORIN.

> It is worth mentioning that there has been an attempt at resurrecting
> SH2 support around 2015 (see https://lwn.net/Articles/647636/) as part
> of the J2 core. This effort led to the addition of FDPIC support for
> SH2A in the musl C library (and therefore proper ELF binaries, with
> shared libraries), but that was never supported in Buildroot. Now that
> the J2 project is essentially dead, there is no reason to bother with
> this.
> 
> Fixes:
> 
>   http://autobuild.buildroot.net/results/63d01d33ae30f86b63b9f42a9fea116f2f3e9005/
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> ---
>  Config.in.legacy                        | 7 +++++++
>  arch/Config.in.sh                       | 5 +----
>  package/uclibc/Config.in                | 1 -
>  toolchain/toolchain-buildroot/Config.in | 2 +-
>  utils/genrandconfig                     | 9 +++------
>  5 files changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/Config.in.legacy b/Config.in.legacy
> index 27f19f14e7..1578ffd016 100644
> --- a/Config.in.legacy
> +++ b/Config.in.legacy
> @@ -146,6 +146,13 @@ endif
>  
>  comment "Legacy options removed in 2022.05"
>  
> +config BR2_sh2a
> +	bool "sh2a architecture support removed"
> +	select BR2_LEGACY
> +	help
> +	  The SuperH 2A (SH2A) architecture was not maintained, and
> +	  broken, so its support was dropped.
> +
>  config BR2_PACKAGE_BOOST_LAYOUT_VERSIONED
>  	bool "boost versioned layout removed"
>  	select BR2_LEGACY
> diff --git a/arch/Config.in.sh b/arch/Config.in.sh
> index a012cbf491..f00954bb5e 100644
> --- a/arch/Config.in.sh
> +++ b/arch/Config.in.sh
> @@ -5,8 +5,6 @@ choice
>  	help
>  	  Specific CPU variant to use
>  
> -config BR2_sh2a
> -	bool "sh2a (SH2A big endian)"
>  config BR2_sh4
>  	bool "sh4 (SH4 little endian)"
>  	select BR2_ARCH_HAS_MMU_MANDATORY
> @@ -22,7 +20,6 @@ config BR2_sh4aeb
>  endchoice
>  
>  config BR2_ARCH
> -	default "sh2a"		if BR2_sh2a
>  	default "sh4"		if BR2_sh4
>  	default "sh4eb"		if BR2_sh4eb
>  	default "sh4a"		if BR2_sh4a
> @@ -33,7 +30,7 @@ config BR2_NORMALIZED_ARCH
>  
>  config BR2_ENDIAN
>  	default "LITTLE"	if BR2_sh4 || BR2_sh4a
> -	default "BIG"		if BR2_sh2a || BR2_sh4eb || BR2_sh4aeb
> +	default "BIG"		if BR2_sh4eb || BR2_sh4aeb
>  
>  config BR2_READELF_ARCH_NAME
>  	default "Renesas / SuperH SH"
> diff --git a/package/uclibc/Config.in b/package/uclibc/Config.in
> index 2091166b62..310414bebc 100644
> --- a/package/uclibc/Config.in
> +++ b/package/uclibc/Config.in
> @@ -124,7 +124,6 @@ config BR2_UCLIBC_MIPS_NAN
>  
>  config BR2_UCLIBC_SH_TYPE
>  	string
> -	default "SH2A" if BR2_sh2a
>  	default "SH4"  if BR2_sh4 || BR2_sh4eb
>  	depends on BR2_UCLIBC_TARGET_ARCH = "sh"
>  
> diff --git a/toolchain/toolchain-buildroot/Config.in b/toolchain/toolchain-buildroot/Config.in
> index 4004c0edf8..be89f68ab5 100644
> --- a/toolchain/toolchain-buildroot/Config.in
> +++ b/toolchain/toolchain-buildroot/Config.in
> @@ -31,7 +31,7 @@ config BR2_TOOLCHAIN_BUILDROOT_UCLIBC
>  		   BR2_arm     || BR2_armeb    || \
>  		   BR2_i386    || BR2_m68k   || BR2_microblaze || \
>  		   BR2_mips    || BR2_mipsel || BR2_mips64 || BR2_mips64el || \
> -		   BR2_or1k    || BR2_powerpc || BR2_RISCV_64 || BR2_sh2a   || \
> +		   BR2_or1k    || BR2_powerpc || BR2_RISCV_64 || \
>  		   BR2_sh4     || BR2_sh4eb   || BR2_sparc || BR2_xtensa || \
>  		   BR2_x86_64
>  	select BR2_TOOLCHAIN_USES_UCLIBC
> diff --git a/utils/genrandconfig b/utils/genrandconfig
> index 59fe34e58d..adefb8f502 100755
> --- a/utils/genrandconfig
> +++ b/utils/genrandconfig
> @@ -237,12 +237,9 @@ def fixup_config(sysinfo, configfile):
>      if 'BR2_PACKAGE_PYTHON3=y\n' in configlines and \
>         BR2_TOOLCHAIN_EXTERNAL_URL + 'mips64el-ctng_n64-linux-gnu.tar.xz"\n' in configlines:
>          return False
> -    # libffi not available on sh2a and ARMv7-M, but propagating libffi
> -    # arch dependencies in Buildroot is really too much work, so we
> -    # handle this here.
> -    if 'BR2_sh2a=y\n' in configlines and \
> -       'BR2_PACKAGE_LIBFFI=y\n' in configlines:
> -        return False
> +    # libffi not available on ARMv7-M, but propagating libffi arch
> +    # dependencies in Buildroot is really too much work, so we handle
> +    # this here.
>      if 'BR2_ARM_CPU_ARMV7M=y\n' in configlines and \
>         'BR2_PACKAGE_LIBFFI=y\n' in configlines:
>          return False
> -- 
> 2.35.1
> 
> _______________________________________________
> buildroot mailing list
> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 561 099 427 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot