boot: Bring back bootloader builds

This adds back sd-boot builds by using meson compile targets directly.
We can do this now, because userspace binaries use the special
dependency that allows us to easily separate flags, so that we don't
pass anything to EFI builds that shouldn't be passed.

Additionally, we pass a bunch of flags to hopefully disable/override any
distro provided flags that should not be used for EFI binaries.

Fixes: #12275

1 files changed, 23 insertions, 4 deletions

diff --git a/meson.build b/meson.build
index 8c4e50de73..cde0c88e48 100644
--- a/meson.build
+++ b/meson.build
@@ -1972,11 +1972,28 @@ if get_option('bootloader') != 'false' and efi_arch != ''
 elif get_option('bootloader') == 'true' and efi_arch == ''
         error('EFI not supported for this arch.')
 endif
+
+efi_arch_alt = ''
+if efi_arch == 'x64' and cc.links('''
+                #include <limits.h>
+                int main(int argc, char *argv[]) {
+                        return __builtin_popcount(argc - CHAR_MAX);
+                }''', args : ['-m32', '-march=i686'], name : '32bit build possible')
+        efi_arch_alt = 'ia32'
+endif
+
+have_pyelftools = pymod.find_installation('python3', required : false, modules : ['elftools']).found()
+if get_option('bootloader') == 'true' and (not python_39 or not have_pyelftools)
+        error('EFI bootloader support requires Python >= 3.9 and pyelftools.')
+endif
+
 conf.set10(
         'ENABLE_BOOTLOADER',
         get_option('efi') and
         get_option('bootloader') in ['auto', 'true'] and
-        efi_arch != '',
+        efi_arch != '' and
+        python_39 and
+        have_pyelftools,
 )
 
 if get_option('ukify') == 'auto'
@@ -1990,18 +2007,20 @@ conf.set10('ENABLE_UKIFY', want_ukify)
 
 ############################################################
 #
+elf2efi_lds = project_source_root / 'tools/elf2efi.lds'
+elf2efi_py = find_program('tools/elf2efi.py')
+export_dbus_interfaces_py = find_program('tools/dbus_exporter.py')
 generate_gperfs = find_program('tools/generate-gperfs.py')
 make_autosuspend_rules_py = find_program('tools/make-autosuspend-rules.py')
 make_directive_index_py = find_program('tools/make-directive-index.py')
 make_man_index_py = find_program('tools/make-man-index.py')
 meson_render_jinja2 = find_program('tools/meson-render-jinja2.py')
 update_dbus_docs_py = find_program('tools/update-dbus-docs.py')
-update_man_rules_py = find_program('tools/update-man-rules.py')
-update_hwdb_sh = find_program('tools/update-hwdb.sh')
 update_hwdb_autosuspend_sh = find_program('tools/update-hwdb-autosuspend.sh')
+update_hwdb_sh = find_program('tools/update-hwdb.sh')
+update_man_rules_py = find_program('tools/update-man-rules.py')
 update_syscall_tables_sh = find_program('tools/update-syscall-tables.sh')
 xml_helper_py = find_program('tools/xml_helper.py')
-export_dbus_interfaces_py = find_program('tools/dbus_exporter.py')
 
 ############################################################