x86: Allow excluding reset vector code from u-boot

When running from coreboot we don't want this code.

This version works by ifdef-ing out all of the code that would go
into those sections and all the code that refers to it. The sections are
then empty, and the linker will either leave them empty for the loader
to ignore or remove them entirely.

Signed-off-by: Gabe Black <gabeblack@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Gabe Black 2012-11-27 21:08:06 +00:00 committed by Simon Glass
parent 8a487a4417
commit b16f521a5e
4 changed files with 13 additions and 5 deletions

View File

@ -231,8 +231,8 @@ endif
OBJS = $(CPUDIR)/start.o
ifeq ($(CPU),x86)
OBJS += $(CPUDIR)/start16.o
OBJS += $(CPUDIR)/resetvec.o
RESET_OBJS-$(CONFIG_X86_NO_RESET_VECTOR) += $(CPUDIR)/start16.o
RESET_OBJS-$(CONFIG_X86_NO_RESET_VECTOR) += $(CPUDIR)/resetvec.o
endif
ifeq ($(CPU),ppc4xx)
OBJS += $(CPUDIR)/resetvec.o
@ -241,7 +241,7 @@ ifeq ($(CPU),mpc85xx)
OBJS += $(CPUDIR)/resetvec.o
endif
OBJS := $(addprefix $(obj),$(OBJS))
OBJS := $(addprefix $(obj),$(OBJS) $(RESET_OBJS-))
HAVE_VENDOR_COMMON_LIB = $(if $(wildcard board/$(VENDOR)/common/Makefile),y,n)

4
README
View File

@ -3664,6 +3664,10 @@ Low Level (hardware related) configuration options:
be used if available. These functions may be faster under some
conditions but may increase the binary size.
- CONFIG_X86_NO_RESET_VECTOR
If defined, the x86 reset vector code is excluded. You will need
to do this when U-Boot is running from Coreboot.
Freescale QE/FMAN Firmware Support:
-----------------------------------

View File

@ -28,12 +28,13 @@ include $(TOPDIR)/config.mk
LIB = $(obj)lib$(CPU).o
START = start.o start16.o resetvec.o
START-y = start.o
RESET_OBJS-$(CONFIG_X86_NO_RESET_VECTOR) += resetvec.o start16.o
COBJS = interrupts.o cpu.o
SRCS := $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS))
START := $(addprefix $(obj),$(START))
START := $(addprefix $(obj),$(START-y) $(RESET_OBJS-))
all: $(obj).depend $(START) $(LIB)

View File

@ -86,6 +86,8 @@ SECTIONS
__bios_start = LOADADDR(.bios);
__bios_size = SIZEOF(.bios);
#ifndef CONFIG_X86_NO_RESET_VECTOR
/*
* The following expressions place the 16-bit Real-Mode code and
* Reset Vector at the end of the Flash ROM
@ -95,4 +97,5 @@ SECTIONS
. = RESET_VEC_LOC;
.resetvec : AT (CONFIG_SYS_TEXT_BASE + (CONFIG_SYS_MONITOR_LEN - RESET_SEG_SIZE + RESET_VEC_LOC)) { KEEP(*(.resetvec)); }
#endif
}