[Buildroot] [git commit branch/2022.02.x] arch/Config.in: armeb no-MMU is not supported

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=f522e99e2774fb47625a0c4033f103d81b0110a4
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2022.02.x

elf2flt does not support ARM big-endian, so supporting Cortex M3/M4/M7
with armeb is not possibly.

Therefore this commit makes:

 - MMU mandatory on armeb
 - Prevents from seeing Cortex M3/M4/M7 on armeb

Fixes:

  http://autobuild.buildroot.net/results/9bca0cbfb6a66c455e74ad194526bca942665978/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
(cherry picked from commit c9b39a81b566f827686d41682ae29ccfdaead4ef)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 arch/Config.in     | 2 +-
 arch/Config.in.arm | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/Config.in b/arch/Config.in
index 1ea4e21413..1665009a62 100644
--- a/arch/Config.in
+++ b/arch/Config.in
@@ -49,7 +49,7 @@ config BR2_arm
 
 config BR2_armeb
 	bool "ARM (big endian)"
-	# MMU support is set by the subarchitecture file, arch/Config.in.arm
+	select BR2_ARCH_HAS_MMU_MANDATORY
 	help
 	  ARM is a 32-bit reduced instruction set computer (RISC)
 	  instruction set architecture (ISA) developed by ARM Holdings.
diff --git a/arch/Config.in.arm b/arch/Config.in.arm
index 85040ac89f..657923f14b 100644
--- a/arch/Config.in.arm
+++ b/arch/Config.in.arm
@@ -259,6 +259,8 @@ config BR2_pj4
 	select BR2_ARM_CPU_ARMV7A
 	select BR2_ARCH_HAS_MMU_OPTIONAL
 
+# Cortex-M cores are only supported for little endian configurations
+if BR2_arm
 comment "armv7m cores"
 config BR2_cortex_m3
 	bool "cortex-M3"
@@ -275,6 +277,7 @@ config BR2_cortex_m7
 	select BR2_ARM_CPU_MAYBE_HAS_FPV5
 	select BR2_ARM_CPU_ARMV7M
 	select BR2_ARCH_NEEDS_GCC_AT_LEAST_5
+endif # BR2_arm
 endif # !BR2_ARCH_IS_64
 
 comment "armv8 cores"