MIPS: Clean up the calculation of VMLINUZ_LOAD_ADDRESS

We have calculated VMLINUZ_LOAD_ADDRESS in shell, which is indecipherable. This
patch rewrites it in C.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
To: linux-mips <linux-mips@linux-mips.org>
Cc: Alexander Clouter <alex@digriz.org.uk>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alexander Clouter <alex@digriz.org.uk>
Patchwork: https://patchwork.linux-mips.org/patch/1324/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/boot/.gitignore

@@ -3,3 +3,4 @@ elf2ecoff
 vmlinux.*
 zImage
 zImage.tmp
+calc_vmlinuz_load_addr

arch/mips/boot/compressed/Makefile

@@ -12,14 +12,6 @@
 # Author: Wu Zhangjin <wuzhangjin@gmail.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 -n $$(($(VMLINUX_SIZE) + (65536 - $(VMLINUX_SIZE) % 65536))))
-# VMLINUZ_LOAD_ADDRESS = concat "high32 of VMLINUX_LOAD_ADDRESS" and "(low32 of VMLINUX_LOAD_ADDRESS) + VMLINUX_SIZE"
-HIGH32 := $(shell A=$(VMLINUX_LOAD_ADDRESS); [ $${\#A} -gt 10 ] && expr substr "$(VMLINUX_LOAD_ADDRESS)" 3 $$(($${\#A} - 10)))
-LOW32 := $(shell [ -n "$(HIGH32)" ] && A=11 || A=3; expr substr "$(VMLINUX_LOAD_ADDRESS)" $${A} 8)
-VMLINUZ_LOAD_ADDRESS := 0x$(shell [ -n "$(VMLINUX_SIZE)" -a -n "$(LOW32)" ] && printf "$(HIGH32)%08x" $$(($(VMLINUX_SIZE) + 0x$(LOW32))))
-
 # set the default size of the mallocing area for decompressing
 BOOT_HEAP_SIZE := 0x400000
 
@@ -63,10 +55,18 @@ OBJCOPYFLAGS_piggy.o := --add-section=.image=$(obj)/vmlinux.bin.z \
 $(obj)/piggy.o: $(obj)/dummy.o $(obj)/vmlinux.bin.z FORCE
 	$(call if_changed,objcopy)
 
-LDFLAGS_vmlinuz := $(LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T
-vmlinuz: $(src)/ld.script $(vmlinuzobjs-y) $(obj)/piggy.o
-	$(call cmd,ld)
-	$(Q)$(OBJCOPY) $(OBJCOPYFLAGS) $@
+# Calculate the load address of the compressed kernel image
+hostprogs-y := calc_vmlinuz_load_addr
+
+VMLINUZ_LOAD_ADDRESS = $(shell $(obj)/calc_vmlinuz_load_addr \
+		$(objtree)/$(KBUILD_IMAGE) $(VMLINUX_LOAD_ADDRESS))
+
+vmlinuzobjs-y += $(obj)/piggy.o
+
+quiet_cmd_zld = LD      $@
+      cmd_zld = $(LD) $(LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T $< $(vmlinuzobjs-y) -o $@
+vmlinuz: $(src)/ld.script $(vmlinuzobjs-y) $(obj)/calc_vmlinuz_load_addr
+	$(call cmd,zld)
 
 #
 # Some DECstations need all possible sections of an ECOFF executable
@@ -76,7 +76,7 @@ ifdef CONFIG_MACH_DECSTATION
 endif
 
 # elf2ecoff can only handle 32bit image
-hostprogs-y := ../elf2ecoff
+hostprogs-y += ../elf2ecoff
 
 ifdef CONFIG_32BIT
 	VMLINUZ = vmlinuz