MIPS: Add support for GZIP / BZIP2 / LZMA compressed kernel images

This patch helps to generate smaller kernel images for linux-MIPS,

Here is the effect when using lzma:

$ ls -sh vmlinux
7.1M vmlinux
$ ls -sh vmlinuz
1.5M vmlinuz

Have tested the 32bit kernel on Qemu/Malta and 64bit kernel on FuLoong
Mini PC. both of them work well. and also, tested by Alexander Clouter
on an AR7 based Linksys WAG54Gv2, and by Manuel Lauss on an Alchemy
board.

This -v2 version incorporate the feedback from Ralf, and add the
following changes:

1. add .ecoff, .bin, .erec format support
2. only enable it and the debug source code for the machines we tested
3. a dozen of fixups and cleanups

and if you want to enable it for your board, please try to select
SYS_SUPPORTS_ZBOOT for it, and if the board have an 16550 compatible
uart, you can select SYS_SUPPORTS_ZBOOT_UART16550 directly. and then
sending the relative patches to Ralf.

Tested-by: Manuel Lauss <manuel.lauss@googlemail.com>
Tested-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 100 insertions, 0 deletions

diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
new file mode 100644
index 0000000..e27f40b
--- /dev/null
+++ b/arch/mips/boot/compressed/Makefile
@@ -0,0 +1,100 @@
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.
+#
+# Adapted for MIPS Pete Popov, Dan Malek
+#
+# Copyright (C) 1994 by Linus Torvalds
+# Adapted for PowerPC by Gary Thomas
+# modified by Cort (cort@cs.nmt.edu)
+#
+# Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University
+# Author: Wu Zhangjin <wuzj@lemote.com>
+#
+
+# compressed kernel load addr: VMLINUZ_LOAD_ADDRESS > VMLINUX_LOAD_ADDRESS + VMLINUX_SIZE
+VMLINUX_SIZE := $(shell wc -c $(objtree)/$(KBUILD_IMAGE) 2>/dev/null | cut -d' ' -f1)
+VMLINUX_SIZE := $(shell [ -n "$(VMLINUX_SIZE)" ] && echo $$(($(VMLINUX_SIZE) + (65536 - $(VMLINUX_SIZE) % 65536))))
+VMLINUZ_LOAD_ADDRESS := 0x$(shell [ -n "$(VMLINUX_SIZE)" ] && printf %x $$(($(VMLINUX_LOAD_ADDRESS) + $(VMLINUX_SIZE))))
+
+# set the default size of the mallocing area for decompressing
+BOOT_HEAP_SIZE := 0x400000
+
+# Disable Function Tracer
+KBUILD_CFLAGS := $(shell echo $(KBUILD_CFLAGS) | sed -e "s/-pg//")
+
+KBUILD_CFLAGS := $(LINUXINCLUDE) $(KBUILD_CFLAGS) -D__KERNEL__ \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull" \
+
+KBUILD_AFLAGS := $(LINUXINCLUDE) $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
+	-DKERNEL_ENTRY=0x$(shell $(NM) $(objtree)/$(KBUILD_IMAGE) 2>/dev/null | grep " kernel_entry" | cut -f1 -d \ ) \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE)
+
+obj-y := $(obj)/head.o $(obj)/decompress.o $(obj)/dbg.o
+
+obj-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART16550) += $(obj)/uart-16550.o
+
+OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary -R .comment -S
+$(obj)/vmlinux.bin: $(KBUILD_IMAGE)
+	$(call if_changed,objcopy)
+
+suffix_$(CONFIG_KERNEL_GZIP)  = gz
+suffix_$(CONFIG_KERNEL_BZIP2) = bz2
+suffix_$(CONFIG_KERNEL_LZMA)  = lzma
+tool_$(CONFIG_KERNEL_GZIP)    = gzip
+tool_$(CONFIG_KERNEL_BZIP2)   = bzip2
+tool_$(CONFIG_KERNEL_LZMA)    = lzma
+$(obj)/vmlinux.$(suffix_y): $(obj)/vmlinux.bin
+	$(call if_changed,$(tool_y))
+
+$(obj)/piggy.o: $(obj)/vmlinux.$(suffix_y) $(obj)/dummy.o
+	$(Q)$(OBJCOPY) $(OBJCOPYFLAGS) \
+		--add-section=.image=$< \
+		--set-section-flags=.image=contents,alloc,load,readonly,data \
+		$(obj)/dummy.o $@
+
+LDFLAGS_vmlinuz := $(LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T
+vmlinuz: $(src)/ld.script $(obj-y) $(obj)/piggy.o
+	$(call if_changed,ld)
+	$(Q)$(OBJCOPY) $(OBJCOPYFLAGS) -R .comment -R .stab -R .stabstr -R .initrd -R .sysmap $@
+
+#
+# Some DECstations need all possible sections of an ECOFF executable
+#
+ifdef CONFIG_MACH_DECSTATION
+  E2EFLAGS = -a
+else
+  E2EFLAGS =
+endif
+
+# elf2ecoff can only handle 32bit image
+
+ifdef CONFIG_32BIT
+	VMLINUZ = vmlinuz
+else
+	VMLINUZ = vmlinuz.32
+endif
+
+vmlinuz.32: vmlinuz
+	$(Q)$(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@
+
+vmlinuz.ecoff: $(obj)/../elf2ecoff $(VMLINUZ)
+	$(Q)$(obj)/../elf2ecoff $(VMLINUZ) vmlinuz.ecoff $(E2EFLAGS)
+
+$(obj)/../elf2ecoff: $(src)/../elf2ecoff.c
+	$(Q)$(HOSTCC) -o $@ $^
+
+drop-sections	= .reginfo .mdebug .comment .note .pdr .options .MIPS.options
+strip-flags	= $(addprefix --remove-section=,$(drop-sections))
+
+OBJCOPYFLAGS_vmlinuz.bin := $(OBJCOPYFLAGS) -O binary $(strip-flags)
+vmlinuz.bin: vmlinuz
+	$(call if_changed,objcopy)
+
+OBJCOPYFLAGS_vmlinuz.srec := $(OBJCOPYFLAGS) -S -O srec $(strip-flags)
+vmlinuz.srec: vmlinuz
+	$(call if_changed,objcopy)
+
+clean:
+clean-files += *.o \
+	       vmlinu*