[PATCH] MIPS: fix vmlinuz build when only 32bit math shell is available

[Alexander Clouter <alex@digriz.org.uk>]

Counter to the documentation for the dash shell, it seems that on my
x86_64 filth under Debian only does 32bit math.  As I have configured
my lapdog to use 'dash' for non-interactive tasks I run into problems
when compiling a compressed kernel.

I play with the AR7 platform, so VMLINUX_LOAD_ADDRESS is
0xffffffff94100000, and for a (for example) 4MiB kernel
VMLINUZ_LOAD_ADDRESS is made out to be:
----
alex@berk:~$ bash -c 'printf "%x\n" $((0xffffffff94100000 + 0x400000))'
ffffffff94500000
alex@berk:~$ dash -c 'printf "%x\n" $((0xffffffff94100000 + 0x400000))'
80000000003fffff
----

The former is obviously correct whilst the later breaks things royally.

This patch fixes vmlinuz kernel builds on systems where only a 32bit
math enabled shell is a available.  It does this by bringing 'bc' back
in as a build dependency (Wu Zhangjin had orginally used 'bc' but I had
suggested he 'fixes' the original dependency *sigh*) but things now seem
to work as expected.

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
---
 arch/mips/boot/compressed/Makefile |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
index 671d344..65d1adf 100644
--- a/arch/mips/boot/compressed/Makefile
+++ b/arch/mips/boot/compressed/Makefile
@@ -14,8 +14,10 @@
 
 # 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))))
+VMLINUX_SIZE := $(shell printf %X $$(($(VMLINUX_SIZE) + (65536 - $(VMLINUX_SIZE) % 65536))))
+VMLINUZ_LOAD_ADDRESS := $(shell A=$(VMLINUX_LOAD_ADDRESS); A=$${A\#0xffffffff}; echo $${A\#0x} | tr a-f A-F)
+VMLINUZ_LOAD_ADDRESS := $(shell echo "obase=16; ibase=16; $(VMLINUZ_LOAD_ADDRESS) + $(VMLINUX_SIZE)" | bc)
+VMLINUZ_LOAD_ADDRESS := $(shell A=$(VMLINUX_LOAD_ADDRESS); [ "$${A\#0xffffffff}" = "$${A}" ] && echo 0x$(VMLINUZ_LOAD_ADDRESS) || echo 0xffffffff$(VMLINUZ_LOAD_ADDRESS))
 
 # set the default size of the mallocing area for decompressing
 BOOT_HEAP_SIZE := 0x400000
-- 
1.6.6