The real-mode emulator that Windows 7 uses to execute the vga bios rom
becomes very confused when the code tries to dereference the stack
pointer instead of using the frame pointer, leading to corruption of
parameters passed on the stack from one function to another.
Signed-off-by: Julian Pidancet <julian.pidancet@gmail.com>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
$(call cc-option,$(CC),-Wtype-limits,) \
-m32 -march=i386 -mregparm=3 -mpreferred-stack-boundary=2 \
-mrtd -minline-all-stringops \
$(call cc-option,$(CC),-Wtype-limits,) \
-m32 -march=i386 -mregparm=3 -mpreferred-stack-boundary=2 \
-mrtd -minline-all-stringops \
- -freg-struct-return -ffreestanding -fomit-frame-pointer \
- -fno-delete-null-pointer-checks \
+ -freg-struct-return -ffreestanding -fno-delete-null-pointer-checks \
-ffunction-sections -fdata-sections -fno-common
COMMONCFLAGS += $(call cc-option,$(CC),-nopie,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector-all,)
-ffunction-sections -fdata-sections -fno-common
COMMONCFLAGS += $(call cc-option,$(CC),-nopie,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector-all,)
-CFLAGS32FLAT = $(COMMONCFLAGS) -g -DMODE16=0 -DMODESEGMENT=0
+CFLAGS32FLAT = $(COMMONCFLAGS) -DMODE16=0 -DMODESEGMENT=0 -g -fomit-frame-pointer
CFLAGSSEG = $(COMMONCFLAGS) -DMODESEGMENT=1 -fno-defer-pop \
$(call cc-option,$(CC),-fno-jump-tables,-DMANUAL_NO_JUMP_TABLE) \
$(call cc-option,$(CC),-fno-tree-switch-conversion,)
CFLAGSSEG = $(COMMONCFLAGS) -DMODESEGMENT=1 -fno-defer-pop \
$(call cc-option,$(CC),-fno-jump-tables,-DMANUAL_NO_JUMP_TABLE) \
$(call cc-option,$(CC),-fno-tree-switch-conversion,)
-CFLAGS32SEG = $(CFLAGSSEG) -DMODE16=0 -g
+CFLAGS32SEG = $(CFLAGSSEG) -DMODE16=0 -g -fomit-frame-pointer
CFLAGS16INC = $(CFLAGSSEG) -DMODE16=1 \
$(call cc-option,$(CC),--param large-stack-frame=4,-fno-inline)
CFLAGS16INC = $(CFLAGSSEG) -DMODE16=1 \
$(call cc-option,$(CC),--param large-stack-frame=4,-fno-inline)
-CFLAGS16 = $(CFLAGS16INC) -g
+CFLAGS16 = $(CFLAGS16INC) -g -fomit-frame-pointer
all: $(OUT) $(OUT)bios.bin
all: $(OUT) $(OUT)bios.bin
SRCVGA=src/output.c src/util.c vgasrc/vga.c vgasrc/vgafb.c vgasrc/vgaio.c \
vgasrc/vgatables.c vgasrc/vgafonts.c vgasrc/clext.c
SRCVGA=src/output.c src/util.c vgasrc/vga.c vgasrc/vgafb.c vgasrc/vgaio.c \
vgasrc/vgatables.c vgasrc/vgafonts.c vgasrc/clext.c
-$(OUT)vgaccode.16.s: $(OUT)autoconf.h ; $(call whole-compile, $(CFLAGS16) -S -Isrc, $(SRCVGA),$@)
+CFLAGS16VGA = $(CFLAGS16INC) -g -Isrc
+
+$(OUT)vgaccode.16.s: $(OUT)autoconf.h ; $(call whole-compile, $(CFLAGS16VGA) -S, $(SRCVGA),$@)
$(OUT)vgalayout16.o: vgaentry.S $(OUT)vgaccode.16.s $(OUT)asm-offsets.h
@echo " Compiling (16bit) $@"
$(OUT)vgalayout16.o: vgaentry.S $(OUT)vgaccode.16.s $(OUT)asm-offsets.h
@echo " Compiling (16bit) $@"