Add vgabios build rules to roms/Makefile

This patch adds some glue to roms/Makefile to build vgabios binaries for
qemu.  It covers both the lgpl'ed vgabios implementation used by qemu
traditionally and the new seabios implementation.

The purpose of this patch is to (a) document the vgabios build process
and (b) simplify seavgabios testing for those who want to play with it.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

roms/Makefile

 
+vgabios_variants := stdvga cirrus vmware qxl
+
 default:
 	@echo "nothing is build by default"
 	@echo "available build targets:"
 	@echo "  bios           -- update bios.bin (seabios)"
+	@echo "  seavgabios     -- update vgabios binaries (seabios)"
+	@echo "  lgplvgabios    -- update vgabios binaries (lgpl)"
 
 bios: config.seabios
 	sh configure-seabios.sh $<
 	make -C seabios out/bios.bin
 	cp seabios/out/bios.bin ../pc-bios/bios.bin
+
+seavgabios: $(patsubst %,seavgabios-%,$(vgabios_variants))
+
+seavgabios-%: config.vga.%
+	sh configure-seabios.sh $<
+	make -C seabios out/vgabios.bin
+	cp seabios/out/vgabios.bin ../pc-bios/vgabios-$*.bin
+
+lgplvgabios: $(patsubst %,lgplvgabios-%,$(vgabios_variants))
+
+lgplvgabios-%:
+	make -C vgabios vgabios-$*.bin
+	cp vgabios/VGABIOS-lgpl-latest.$*.bin ../pc-bios/vgabios-$*.bin

roms/config.vga.cirrus

+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_CIRRUS=y
+CONFIG_VGA_PCI=y

roms/config.vga.isavga

+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_BOCHS=y
+CONFIG_VGA_PCI=n

roms/config.vga.qxl

+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_BOCHS=y
+CONFIG_VGA_PCI=y
+CONFIG_OVERRIDE_PCI_ID=y
+CONFIG_VGA_VID=0x1b36
+CONFIG_VGA_DID=0x0100

roms/config.vga.stdvga

+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_BOCHS=y
+CONFIG_VGA_PCI=y

roms/config.vga.vmware

+CONFIG_BUILD_VGABIOS=y
+CONFIG_VGA_BOCHS=y
+CONFIG_VGA_PCI=y
+CONFIG_OVERRIDE_PCI_ID=y
+CONFIG_VGA_VID=0x15ad
+CONFIG_VGA_DID=0x0405