WiP: have modules built to be optimized for space (-Os)

Adresses @easrentai suggestion to pass modules build optimization for space here: linuxboot#590 (comment)

Uniformized module's $(CROSS_TOOLS) being passed as environment variable, prior of ./configure call

Limitations:
- busybox don't seem to take Os into consideration when applied, no change to module yet.
- kexec applies both O2 and Os, no change to module yet.
- Kernel is already optimized for size (CONFIG_CC_OPTIMIZE_FOR_SIZE as Kconfig option), and kernel modules stripped prior of inserted in initrd, compressed with xz. Nothing else can be done here unless lto

Next steps:
- Go LTO for kernel and modules? But, I was not successful going that way in the past, maybe musl-cross-make has changed.
- Not sure if I read correctly, but -Oz may have happened under GCC 12.1, but not sure if apple relative or FSS GCC. Opened an issue over musl-cross-make, but the project is conservative on used GCC version.

Attempt to contribute to linuxboot#590 by reducing payload's footprint

modules/busybox

@@ -12,6 +12,7 @@ busybox_configure := $(MAKE) CC="$(heads_cc)" oldconfig
 busybox_config := config/busybox.config
 busybox_output := busybox
 busybox_target := \
+	HOSTCXXFLAGS="-Os" \
 	$(CROSS_TOOLS) \
 	$(MAKE_JOBS) \
 

modules/flashrom

@@ -30,7 +30,7 @@ flashrom_target := \
 	INSTALL="$(INSTALL)" \
 	DESTDIR="$(INSTALL)" \
 	LIBS_BASE="$(INSTALL)" \
-	CFLAGS="-I$(INSTALL)/include/libusb-1.0 -I$(INSTALL)/include/pci" \
+	CFLAGS="-Os -I$(INSTALL)/include/libusb-1.0 -I$(INSTALL)/include/pci" \
 	LDFLAGS="-L$(INSTALL)/lib" \
 	$(flashrom_cfg) \
 	$(CROSS_TOOLS) \

modules/flashtools

@@ -10,7 +10,7 @@ flashtools_hash := 81b3c1f12318bd2942b426a99638e23d24e85819227653cd3b9302fbfc43b
 
 flashtools_target := \
 	$(CROSS_TOOLS) \
-	CFLAGS="-I$(INSTALL)/include" \
+	CFLAGS="-Os -I$(INSTALL)/include" \
 	LDFLAGS="-L$(INSTALL)/lib" \
 
 flashtools_output := \

modules/kexec

@@ -6,7 +6,9 @@ kexec_tar := kexec-tools-$(kexec_version).tar.gz
 kexec_url := https://kernel.org/pub/linux/utils/kernel/kexec/$(kexec_tar)
 kexec_hash := 40623d4321be2865ef9ea2cd6ec998d31dcf93d0f74353cbd3aa06d8821e3e41
 
-kexec_configure := ./configure \
+kexec_configure := \
+	CFLAGS="-g -Os -fno-strict-aliasing -Wall -Wstrict-prototypes" \
+	./configure \
 	$(CROSS_TOOLS) \
 	--host $(MUSL_ARCH)-elf-linux \
 	--target $(MUSL_ARCH) \

modules/libusb

@@ -9,7 +9,9 @@ libusb_url := https://downloads.sourceforge.net/project/libusb/libusb-1.0/libusb
 libusb_url := https://github.com/libusb/libusb/releases/download/v$(libusb_version)/$(libusb_tar)
 libusb_hash := 7dce9cce9a81194b7065ee912bcd55eeffebab694ea403ffb91b67db66b1824b
 
-libusb_configure := ./configure\
+libusb_configure := \
+	CFLAGS="-Os" \
+	./configure \
 	$(CROSS_TOOLS)\
 	--host $(MUSL_ARCH)-elf-linux\
 	--prefix "/"\

modules/libusb-compat

@@ -11,7 +11,9 @@ libusb-compat_tar := libusb-compat-$(libusb-compat_version).tar.bz2
 libusb-compat_url := https://downloads.sourceforge.net/project/libusb/libusb-compat-0.1/libusb-compat-$(libusb-compat_version)/$(libusb-compat_tar)
 libusb-compat_hash := 404ef4b6b324be79ac1bfb3d839eac860fbc929e6acb1ef88793a6ea328bc55a
 
-libusb-compat_configure := ./configure \
+libusb-compat_configure := \
+	CFLAGS="-Os" \
+	./configure \
 	$(CROSS_TOOLS) \
 	--host $(MUSL_ARCH)-elf-linux \
 	--prefix "/" \

modules/newt

@@ -20,7 +20,8 @@ newt_output := \
 newt_libraries := \
 	libnewt.so.0.52 \
 
-newt_configure := ./autogen.sh; ./configure \
+newt_configure := \
+	./autogen.sh && CFLAGS="-Os" ./configure \
 	$(CROSS_TOOLS) \
 	--prefix "/" \
 	--host $(MUSL_ARCH)-elf-linux \

modules/npth

@@ -6,7 +6,9 @@ npth_tar := npth-$(npth_version).tar.bz2
 npth_url := https://gnupg.org/ftp/gcrypt/npth/$(npth_tar)
 npth_hash := 1393abd9adcf0762d34798dc34fdcf4d0d22a8410721e76f1e3afcd1daa4e2d1
 
-npth_configure := ./configure \
+npth_configure := \
+	CFLAGS="-Os" \
+	./configure \
 	$(CROSS_TOOLS) \
 	--host $(MUSL_ARCH)-linux-musl \
 	--prefix "/" \

modules/qrencode

@@ -8,7 +8,9 @@ qrencode_hash := e794e26a96019013c0e3665cb06b18992668f352c5553d0a553f5d144f7f2a7
 
 qrencode_libraries := .libs/libqrencode.so.3
 
-qrencode_configure := ./configure \
+qrencode_configure := \
+	CFLAGS="-Os" \
+	./configure \
 	$(CROSS_TOOLS) \
 	--prefix "/" \
 	--without-tools \