C kernel runs now after fixing bootloader and build, beginnings of a REPL

Makefile

@@ -1,15 +1,15 @@
 all: boot.img kernel.bin
 
 src/%.o: src/%.c
-	bcc -ansi -3 -c -o $@ $<
+	bcc -ansi -0 -c -o $@ $<
 
 kernel.bin: src/kernel.o
-	ld86 -T0x1000 -M -o $@ $^
+	ld86 -d -M -o $@ $^ | tee ld86.out
 
 asm/kernel_syms.S: kernel.bin
-	objdump86 kernel.bin | \
-		grep -E "^[0-9]+ T _.*" | \
-		python -c "import sys; print '\n'.join([\"_extern_c%s:\n    jmp 0x1000:0x%04x\" % (x.split(' ')[2].strip('\n'), int(x.split(' ')[0].lstrip('0'), 16)-0x1000) for x in sys.stdin.readlines()])" > asm/kernel_syms.S
+	cat ld86.out | \
+		grep -E "^\s+kernel\s+[a-zA-Z0-9_]+  0  [0-9]+" | \
+		python -c "import sys; print '\n'.join([\"_extern_c%s:\n    jmp 0x1000:0x%04x\" % (x.lstrip(' ').replace('kernel', '').lstrip(' ').split(' ')[0], int(x.lstrip(' ').replace('kernel', '').lstrip(' ').split(' ')[4], 16)) for x in sys.stdin.readlines()])" > asm/kernel_syms.S
 
 boot.bin: asm/kernel_syms.S asm/bootloader.S asm/bootloader.S
 	cd asm && nasm bootloader.S -f bin -o ../$@
@@ -18,7 +18,10 @@ asm/%.o: asm/%.S
 	nasm $< -f as86 -o $@
 
 boot.img: boot.bin kernel.bin
-	cat $^ > $@
+	dd if=/dev/zero of=boot.img ibs=1k count=1440
+	cat $^ > boot.tmp
+	dd if=boot.tmp of=boot.img conv=notrunc
+	rm -f boot.tmp
 
 test: boot.img
 	bochs -f bochsrc -q