From bc28c3df6fb6a812de689a25d0d2dea1388b4b9d Mon Sep 17 00:00:00 2001
From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Thu, 31 Jul 2025 15:44:01 +0200
Subject: [PATCH] arch/loongarch: Mark lp64f and lp64s as broken

Toolchain failed to bootstrap with LP64F and LP64S ABIs.

As reported by Julien in [1]:

Testing the "lp64f" ABI with commands:

     cat >.config <<EOF
     BR2_loongarch64=y
     BR2_LOONGARCH_FPU_32=y
     BR2_LINUX_KERNEL=y
     BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
     BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
     BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF=y
     BR2_TARGET_ROOTFS_EXT2=y
     # BR2_TARGET_ROOTFS_TAR is not set
     EOF
     make olddefconfig
     make

fails in host-gcc-initial with output:

     Assembler messages:
     /tmp/ccEkwSsD.s:28: Error: register save offset not a multiple of 8
     /tmp/ccEkwSsD.s:30: Error: register save offset not a multiple of 8
     /tmp/ccEkwSsD.s:50: Error: register save offset not a multiple of 8

See also autobuilder failures such as [2].

Testing the "lp46s" ABI with commands:

     cat >.config <<EOF
     BR2_loongarch64=y
     BR2_LOONGARCH_FPU_NONE=y
     BR2_LINUX_KERNEL=y
     BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
     BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
     BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF=y
     BR2_TARGET_ROOTFS_EXT2=y
     # BR2_TARGET_ROOTFS_TAR is not set
     EOF
     make olddefconfig
     make

fails in host-gcc-final with output:

     /buildroot/output/host/loongarch64-buildroot-linux-gnusf/bin/ld: cannot find crti.o: No such file or directory
     /buildroot/output/host/loongarch64-buildroot-linux-gnusf/bin/ld: cannot find -lc: No such file or directory
     /buildroot/output/host/loongarch64-buildroot-linux-gnusf/bin/ld: cannot find crtn.o: No such file or directory

See also autobuilder failures with as [3].

This commit marks those ABIs as broken at the moment to allow time
for investigation. Also, since gcc defaults to the "lp64d" ABI which
requires a 64bit FPU is present, the BR2_LOONGARCH_FPU_32 and
BR2_LOONGARCH_FPU_NONE options also needs to be marked as broken
as well. See [4].

[1] https://lore.kernel.org/buildroot/e17da108d1fb4e6abda26445dc053b35@free.fr/
[2] https://autobuild.buildroot.org/results/f98570293823867e6c43a1672e1a4b43ca1e4be5
[3] https://autobuild.buildroot.org/results/cf56c37fabcae964dbf4f96eb43a7e4d964452b6
[4] https://lore.kernel.org/buildroot/7b0f1cb629fce8a57d9b644b8beb8b2a@free.fr/

Cc: Mingcong Bai <jeffbai@aosc.io>
Cc: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[Julien:
 - add link to mailing list discussion
 - add configuration to reproduce issues to help future investigations
 - add links to autobuilder failures in commit log
 - mark BR2_LOONGARCH_FPU_{32,NONE} as broken
]
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
---
 arch/Config.in.loongarch | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/Config.in.loongarch b/arch/Config.in.loongarch
index fa1b13bc52..4b50b98710 100644
--- a/arch/Config.in.loongarch
+++ b/arch/Config.in.loongarch
@@ -38,12 +38,16 @@ config BR2_LOONGARCH_FPU_64
 
 config BR2_LOONGARCH_FPU_32
 	bool "32"
+	# Only supported by lp64s and lp64f ABIs which are marked as broken
+	depends on BR2_BROKEN
 	help
 	  Allow the use of hardware floating-point instructions for
 	  32-bit operations only.
 
 config BR2_LOONGARCH_FPU_NONE
 	bool "none"
+	# Only supported by lp64s ABI which is marked as broken
+	depends on BR2_BROKEN
 	help
 	  Prevent the use of hardware floating-point instructions.
 endchoice
@@ -87,11 +91,15 @@ config BR2_LOONGARCH_ABI_LP64D
 config BR2_LOONGARCH_ABI_LP64F
 	bool "lp64f"
 	depends on BR2_ARCH_IS_64
+	# Failed to build host GCC initial, pending investigation
+	depends on BR2_BROKEN
 	depends on BR2_LOONGARCH_FPU_64 || BR2_LOONGARCH_FPU_32
 
 config BR2_LOONGARCH_ABI_LP64S
 	bool "lp64s"
 	depends on BR2_ARCH_IS_64
+	# GCC can't find libraries, pending investigation
+	depends on BR2_BROKEN
 endchoice
 
 config BR2_ARCH