cbfstool: autocreate trampoline
Add the code necessary to create the linux trampoline blob.
Don't enforce this for the in-coreboot build or use objcopy
to produce linux_trampoline.o as it is a bit trickier to get
all the details right than I had hoped:
- you have to know the elf architecture of the host machine
- you might have to have more tools (xxd, perl, etc) installed
Change-Id: I9b7877c58d90f9fb21d16e0061a31e19fffa2470
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/12505
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/util/cbfstool/Makefile b/util/cbfstool/Makefile
index 085a19a..b595297 100644
--- a/util/cbfstool/Makefile
+++ b/util/cbfstool/Makefile
@@ -4,6 +4,7 @@
CONFIG_FMD_GENPARSER := y
HOSTCC ?= $(CC)
+OBJCOPY ?= objcopy
.PHONY: all
all: $(objutil)/cbfstool/cbfstool \
@@ -17,6 +18,18 @@
$(RM) $(objutil)/cbfstool/fmaptool $(fmapobj)
$(RM) $(objutil)/cbfstool/rmodtool $(rmodobj)
+linux_trampoline.c: linux_trampoline.S
+ rm -f linux_trampoline.c
+ $(CC) -m32 -o linux_trampoline linux_trampoline.S -ffreestanding -nostdlib -nostdinc -Wl,--defsym=_start=0
+ $(OBJCOPY) -Obinary -j .data linux_trampoline trampoline
+ echo "/* This file is automatically generated. Do not manually change */" > trampoline.c
+ xxd -c 16 -i trampoline >> trampoline.c
+ perl -pi -e 's,unsigned int.*$$,,g;s,unsigned char,const unsigned char,g' trampoline.c
+ echo "const void * const trampoline_start = &trampoline;" >> trampoline.c
+ echo "const unsigned long trampoline_size = sizeof trampoline;" >> trampoline.c
+ mv trampoline.c linux_trampoline.c
+ rm linux_trampoline trampoline
+
.SILENT:
include Makefile.inc