Replace meson with Makefile and verify size of bios.bin

.github/workflows/ccpp.yml

@@ -0,0 +1,16 @@
+name: bios-build
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: make
+      run: make
+    - name: Upload bios.bin
+      uses: actions/upload-artifact@v1
+      with:
+        name: bios.bin
+        path: build/bios.bin

.gitignore

@@ -0,0 +1,5 @@
+build
+*.o
+*.d
+*.bin
+*.elf

Makefile

@@ -0,0 +1,80 @@
+CC	?= $(CROSS)gcc
+AS	?= $(CROSS)gcc
+OBJCOPY	?= $(CROSS)objcopy
+O	?= build
+
+all: $O/bios.bin
+ROMSIZE = 65536
+
+$O: ; mkdir -p $@
+
+CFLAGS	= \
+	-W \
+	-Wall \
+	-m32 \
+	-march=i386 \
+	-mregparm=3 \
+	-fno-stack-protector \
+	-fno-delete-null-pointer-checks \
+	-ffreestanding \
+	-mstringop-strategy=rep_byte \
+	-minline-all-stringops \
+	-fno-pic \
+	-Iinclude \
+	-MT $@ \
+	-MMD -MP \
+	-MF $O/$*.d \
+
+ASFLAGS = $(CFLAGS)
+
+LDFLAGS	= \
+	-nostdlib \
+	-m32 \
+	-Wl,--build-id=none \
+	-Wl,-Tflat.lds \
+
+OBJS = \
+	code16.o \
+	code32seg.o \
+	cstart.o \
+	entry.o \
+	fw_cfg.o \
+	hwsetup.o \
+	linuxboot.o \
+	main.o \
+	malloc.o \
+	mptable.o \
+	pci.o \
+	printf.o \
+	string.o \
+	smbios.o \
+	tables.o \
+
+$O/bios.elf: $(addprefix $O/,$(OBJS))
+	$(CC) $(LDFLAGS) -o $@ $^
+
+$O/%.bin: $O/%.elf
+	$(OBJCOPY) \
+		-O binary \
+		-j .text \
+		-j .rodata \
+		-j .data \
+		-j .bss \
+		-j .init \
+		$< \
+		"[email protected]"
+	@if [ `stat -c '%s' "[email protected]"` != $(ROMSIZE) ]; then \
+		echo >&2 '$@ != $(ROMSIZE) bytes!' ; \
+		exit 1 ; \
+	fi
+	mv "[email protected]" "$@"
+
+$O/%.o: %.c | $O
+	$(CC) $(CFLAGS) -c -o $@ $<
+$O/%.o: %.S | $O
+	$(CC) $(ASFLAGS) -c -o $@ $<
+
+clean:
+	$(RM) $O/*.o $O/bios.bin $O/bios.bin.elf $O/*.d
+
+-include $O/*.d

README → README.md

@@ -1,10 +1,13 @@
+[![Build status](../../workflows/bios-build/badge.svg)](../../actions?query=workflow%3Abios-build)
+
 A simple x86 firmware that can boot Linux.
 
 Most of QEMU's startup time is spent:
 
 * in the dynamic linker.  This can be reduced by 150 ms simply by
   compiling a stripped down QEMU:
 
+```
     ./configure --disable-libssh2 --disable-tcmalloc --disable-glusterfs \
         --disable-seccomp --disable-{bzip2,snappy,lzo} --disable-usb-redir \
         --disable-libusb --disable-smartcard-nss --disable-libnfs  \
@@ -14,13 +17,14 @@ Most of QEMU's startup time is spent:
         --disable-fdt --disable-curl --disable-curses --disable-sdl \
         --disable-gtk  --disable-tpm --disable-vte --disable-vnc  \
         --disable-xen --disable-opengl --target-list=x86_64-softmmu
+```
 
 * in the BIOS.  qboot saves another 150 ms.
 
-* until QEMU 2.7+, in fw_cfg.  qboot uses the DMA interface which is pretty
+* until QEMU 2.7+, in `fw_cfg`.  qboot uses the DMA interface which is pretty
   much instantaneous.
 
-Compile qboot
+Compile `qboot`
 =============
 
 Clone the source:
@@ -30,9 +34,9 @@ Clone the source:
 Compile the qboot firmware (you may need to install the relevant build
 time dependancies):
 
-    $ meson build && ninja -C build
+    $ make
 
-The result will be a 64K file named bios.bin under the build/ directory.
+The result will be a 64K file named `build/bios.bin`.
 
 Usage
 =====