Fix arm + riscv support for gnu-efi > 3.0.15

With gnu-efi >= 3.0.16, the binary format assemblage
doesn't work anymore due to lds and crt0 changes.

Hence, with gnu-efi >= 3.0.16, use the efi-app target.
For gnu-efi <= 3.0.15, still use the binary assemblage.

Signed-off-by: Christian Storm <christian.storm@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Makefile.am

@@ -242,15 +242,20 @@ efi_ldflags = \
 	-L $(GNUEFI_LIB_DIR) \
 	$(GNUEFI_LIB_DIR)/crt0-efi-$(ARCH).o
 
+if !ARCH_IS_X86
+# Suppress RWX segment warnings.
+efi_ldflags += $(LDFLAGS_NO_WARN_RWX_SEGMENTS)
+endif
+
 if ARCH_IS_X86
 objcopy_format = --target=efi-app-$(ARCH)
 else
-# aarch64's and arm's objcopy don't understand --target efi-[app|bsdrv|rtdrv],
-# hence set subsystem 0xa (EFI application) and binary format.
+if OBJCOPY_USE_EFI_APP_TARGET
+objcopy_format = --target=efi-app-$(ARCH)
+else
 objcopy_format = -O binary
 efi_ldflags += --defsym=EFI_SUBSYSTEM=0xa
-# Also suppress RWX segment warnings until we have a better solution
-efi_ldflags += $(LDFLAGS_NO_WARN_RWX_SEGMENTS)
+endif
 endif
 
 efi_objects_pre1 = $(efi_sources:.c=.o)
@@ -300,7 +305,7 @@ $(efi_solib): $(efi_objects)
 
 $(efi_loadername): $(efi_solib)
 	$(AM_V_GEN) $(OBJCOPY) -j .text -j .wdfuncs -j .sdata -j .data -j .dynamic \
-	  -j .dynsym -j .rel*  $(objcopy_format) $< $@
+	  -j .dynsym -j .rodata -j .rel*  $(objcopy_format) $< $@
 
 $(kernel_stub_solib): $(kernel_stub_objects)
 	$(AM_V_CCLD)$(LD) $(efi_ldflags) $(kernel_stub_objects) \

configure.ac

@@ -39,6 +39,8 @@ AC_SYS_LARGEFILE
 AC_PROG_CC
 AC_CHECK_TOOL(LD, ld)
 AC_CHECK_TOOL(OBJCOPY, objcopy)
+AC_CHECK_TOOL(GREP, grep)
+AC_CHECK_TOOL(TR, tr)
 
 dnl Dont try to use things like -std=c99 for efi compilation
 GNUEFI_CC=$CC
@@ -221,6 +223,18 @@ if test "x$PKG_CONFIG" = "xno"; then
 	AC_MSG_ERROR([You need to install pkg-config])
 fi
 
+# Note: gnu-efi introduced pkg-config with version 3.0.16
+# GNU_EFI_VERSION resolves to gnu-efi's version without dots, e.g., GNU_EFI_VERSION=3016
+# gnu-efi versions < 3.0.16 resolve to GNU_EFI_VERSION=0
+AC_SUBST([GNU_EFI_VERSION], [$(($PKG_CONFIG --modversion "gnu-efi" 2>/dev/null || echo 0) | $TR -d '.' )])
+
+AC_SUBST([OBJCOPY_HAS_EFI_APP_TARGET], [$($OBJCOPY --info | $GREP -q pei- 2>/dev/null && echo "true")])
+if test -z $OBJCOPY_HAS_EFI_APP_TARGET && test $GNU_EFI_VERSION -gt 0; then
+	AC_MSG_ERROR([objcopy doesn't support --target=efi-app but gnu-efi >= 3.0.16])
+fi
+AM_CONDITIONAL([OBJCOPY_USE_EFI_APP_TARGET],
+	       [test -n $OBJCOPY_HAS_EFI_APP_TARGET && test $GNU_EFI_VERSION -gt 0])
+
 AS_IF([test "x$enable_bootloader" != "xno"],
     [
 	PKG_CHECK_MODULES(LIBPCI, libpci)