configure allows to run a dedicated compiler binary, which is stored in
CC and HOST_CC variables, and overrides the default 'cc' command.

This command however is not used when building ipxe from source.
"make -C roms pxerom" invokes the buildsystem of ipxe.git, which has the
command "gcc" hardcoded. That binary may not be suitable to build ipxe.
Reuse the same compiler command that is used to build qemu by specifying
CC and HOST_CC as make commandline option to override the built-in
defaults of ipxe.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 roms/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/roms/Makefile b/roms/Makefile
index 02b69fbac8..982bf105a3 100644
--- a/roms/Makefile
+++ b/roms/Makefile
@@ -127,11 +127,13 @@ efi-rom-%: build-pxe-roms build-efi-roms
 
 build-pxe-roms:
 	$(MAKE) -C ipxe/src CONFIG=qemu \
+		CC=$(CC) HOST_CC=$(HOST_CC) \
 		CROSS_COMPILE=$(x86_64_cross_prefix) \
 		$(patsubst %,bin/%.rom,$(pxerom_targets))
 
 build-efi-roms: build-pxe-roms
 	$(MAKE) -C ipxe/src CONFIG=qemu \
+		CC=$(CC) HOST_CC=$(HOST_CC) \
 		CROSS_COMPILE=$(x86_64_cross_prefix) \
 		$(patsubst %,bin-i386-efi/%.efidrv,$(pxerom_targets)) \
 		$(patsubst %,bin-x86_64-efi/%.efidrv,$(pxerom_targets))

Am Wed, 18 Apr 2018 10:13:10 +0200
schrieb Olaf Hering <olaf@aepfle.de>:

> configure allows to run a dedicated compiler binary, which is stored in
> CC and HOST_CC variables, and overrides the default 'cc' command.
> This command however is not used when building ipxe from source.
> "make -C roms pxerom" invokes ...

Scratch that patch. make -C operates just below 'roms/' and does not use
results from configure. The CC variable built into make(1) happens to be cc.

Olaf