From 27c524d1743047258f9a6a2ad813f54d35c1f8e8 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Thu, 22 Mar 2018 16:30:41 +0000 Subject: [PATCH] MIPS: Use the entry point from the ELF file header In order to fetch the correct entry point with the ISA bit included, for use by non-ELF boot loaders, parse the output of `objdump -f' for the start address recorded in the kernel executable itself, rather than using `nm' to get the value of the `kernel_entry' symbol. Sign-extend the address retrieved if 32-bit, so that execution is correctly started on 64-bit processors as well. The tool always prints the entry point using either 8 or 16 hexadecimal digits, matching the address width (aka class) of the ELF file, even in the presence of leading zeros. Signed-off-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/18912/ Signed-off-by: James Hogan --- arch/mips/Makefile | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 646a2d9..5e9fce0 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -251,20 +251,12 @@ ifdef CONFIG_PHYSICAL_START load-y = $(CONFIG_PHYSICAL_START) endif -entry-noisa-y = 0x$(shell $(NM) vmlinux 2>/dev/null \ - | grep "\bkernel_entry\b" | cut -f1 -d \ ) -ifdef CONFIG_CPU_MICROMIPS - # - # Set the ISA bit, since the kernel_entry symbol in the ELF will have it - # clear which would lead to images containing addresses which bootloaders may - # jump to as MIPS32 code. - # - entry-y = $(patsubst %0,%1,$(patsubst %2,%3,$(patsubst %4,%5, \ - $(patsubst %6,%7,$(patsubst %8,%9,$(patsubst %a,%b, \ - $(patsubst %c,%d,$(patsubst %e,%f,$(entry-noisa-y))))))))) -else - entry-y = $(entry-noisa-y) -endif +# Sign-extend the entry point to 64 bits if retrieved as a 32-bit number. +entry-y = $(shell $(OBJDUMP) -f vmlinux 2>/dev/null \ + | sed -n '/^start address / { \ + s/^.* //; \ + s/0x\([0-7].......\)$$/0x00000000\1/; \ + s/0x\(........\)$$/0xffffffff\1/; p }') cflags-y += -I$(srctree)/arch/mips/include/asm/mach-generic drivers-$(CONFIG_PCI) += arch/mips/pci/ -- 2.7.4