package/glibc: headers >= 5.4 needed on RISC-V 32-bit

Since glibc 2.33 (upstream commit
7a55dd3fb6d2c307a002a16776be84310b9c8989), headers >= 5.4.0 are needed
to build glibc for RISC-V 32-bit. Indeed
sysdeps/unix/sysv/linux/riscv/configure.ac contains:

if test $libc_cv_riscv_int_abi = ilp32; then
  arch_minimum_kernel=5.4.0
fi

In order to take into account this dependency, we add the appropriate
logic in package/glibc/Config.in and
toolchain/toolchain-buildroot/Config.in.

This change means that if headers < 5.4.0 are selected, then no C
library at all will be available for RISC-V 32-bit, as glibc is the
only C library supporting RISC-V 32-bit currently. However, thanks to
the recent addition of BR2_TOOLCHAIN_BUILDROOT_NONE, the
choice...endchoice for the C library selection will not be empty,
allowing the user to see the Config.in comment explaining why glibc
can't be selected.

Therefore, technically this commit does prevent from creating a
configuration with RISC-V 32-bit and headers < 5.4.0, but it will have
BR2_TOOLCHAIN_BUILDROOT_NONE=y, which is catched by
package/Makefile.in, which aborts the build early on pointing out that
the configuration is invalid.

Fixes:

  http://autobuild.buildroot.net/results/5ca49b2732f68eccb5276e7112f7f496dcc514ee/

Signed-off-by: Thomas Petazzoni <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Signed-off-by: Yann E. MORIN <[email protected]>

package/glibc/Config.in

@@ -34,6 +34,7 @@ config BR2_PACKAGE_GLIBC_SUPPORTS
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10 || !BR2_powerpc64le
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_5 || !BR2_MIPS_NAN_2008
+	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_4 || !BR2_RISCV_32
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0 || !BR2_RISCV_64
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1 || !BR2_arc
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_4 || !BR2_or1k

toolchain/toolchain-buildroot/Config.in

@@ -62,6 +62,10 @@ comment "glibc on RISC-V 64-bit needs a toolchain w/ headers >= 5.0"
 	depends on BR2_RISCV_64
 	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
 
+comment "glibc on RISC-V 32-bit needs a toolchain w/ headers >= 5.4"
+	depends on BR2_RISCV_32
+	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_4
+
 comment "glibc on ARC needs a toolchain w/ headers >= 5.1"
 	depends on BR2_arc
 	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1