Also compile kernel as ELF for easier disassembly

diff --git a/Makefile b/Makefile
index 8d4b3653f3c8f16c9749254f8908bf568e48b17d..ce6fccc146f48fb206005586f2beb4a3c5c5e970 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ CC = i686-elf-gcc
 
 KERNEL_OBJ = kernel/entry.o kernel/arch/x86/tty/tty.o kernel/kernel.o
 
-all: boot.img
+all: boot.img kernel/kernel.elf
 
 boot.img: boot/x86/boot kernel/kernel.bin
        cat boot/x86/boot kernel/kernel.bin > $@
@@ -14,7 +14,7 @@ boot/x86/boot: boot/x86/boot.s boot/x86/a20.s boot/x86/protected.s boot/x86/prin
        $(AS) -f bin boot/x86/boot.s -o $@
 
 kernel/kernel.bin: ${KERNEL_OBJ}
-       $(LD) -o $@ -T kernel/linker.ld ${KERNEL_OBJ} --oformat=binary
+       $(LD) -o $@ -T kernel/linker.ld ${KERNEL_OBJ} 
 
 kernel/entry.o: kernel/entry.s
        $(AS) -f elf kernel/entry.s -o $@
@@ -25,6 +25,9 @@ kernel/arch/x86/tty/tty.o: kernel/arch/x86/tty/tty.c
 kernel/kernel.o: kernel/kernel.c
        $(CC) -g -o $@ -Iinclude/arch/x86 -ffreestanding -c kernel/kernel.c
 
+kernel/kernel.elf: kernel/kernel.bin
+       $(LD) -o $@ -T kernel/linker.ld ${KERNEL_OBJ} --oformat=elf32-i386
+
 clean:
        rm boot/x86/boot kernel/kernel.bin ${KERNEL_OBJ} boot.img
 

diff --git a/kernel/arch/x86/tty/tty.c b/kernel/arch/x86/tty/tty.c
index c1bb0a5242e53586d53d39d4b71a11b0c7f85e03..d3ef87b1d862290002347932aaa03c8b02f2e4b0 100644 (file)
--- a/kernel/arch/x86/tty/tty.c
+++ b/kernel/arch/x86/tty/tty.c
@@ -1,7 +1,7 @@
 #define VGA_WIDTH 80
 #define VGA_HEIGHT 25
 
-char *video_memory = (char *) 0xB8000; /* VGA VRAM starts at 0xB8000 */
+volatile char *video_memory = (char *) 0xB8000; /* VGA VRAM starts at 0xB8000 */
 
 static int cursor_x = 0;
 static int cursor_y = 0;