ARM: replace unnecessary perl with sed and the shell $(( )) operator

You can build a kernel in a cross compiling environment that doesn't
have perl in the $PATH. Commit 429f7a062e3b broke that for 32 bit
ARM. Fix it.

As reported by Stephen Rothwell, it appears that the symbols can be
either part of the BSS section or absolute symbols depending on the
binutils version.  When they're an absolute symbol, the $(( ))
operator errors out and the build fails.  Fix this as well.

Fixes: 429f7a062e3b ("ARM: decompressor: fix BSS size calculation")
Reported-by: Rob Landley <rob@landley.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 45a6b9b7af2a56f179427d353ad70c3cd920bb69..6a4e7341ecd33284f835a65fcc83a3e52ee4d524 100644 (file)
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -117,11 +117,9 @@ ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 asflags-y := -DZIMAGE
 
 # Supply kernel BSS size to the decompressor via a linker symbol.
-KBSS_SZ = $(shell $(CROSS_COMPILE)nm $(obj)/../../../../vmlinux | \
-               perl -e 'while (<>) { \
-                       $$bss_start=hex($$1) if /^([[:xdigit:]]+) B __bss_start$$/; \
-                       $$bss_end=hex($$1) if /^([[:xdigit:]]+) B __bss_stop$$/; \
-               }; printf "%d\n", $$bss_end - $$bss_start;')
+KBSS_SZ = $(shell echo $$(($$($(CROSS_COMPILE)nm $(obj)/../../../../vmlinux | \
+               sed -n -e 's/^\([^ ]*\) [AB] __bss_start$$/-0x\1/p' \
+                      -e 's/^\([^ ]*\) [AB] __bss_stop$$/+0x\1/p') )) )
 LDFLAGS_vmlinux = --defsym _kernel_bss_size=$(KBSS_SZ)
 # Supply ZRELADDR to the decompressor via a linker symbol.
 ifneq ($(CONFIG_AUTO_ZRELADDR),y)