Move kernel libs into subdir, create NBP-specific entrypoint

Makefile

@@ -1,5 +1,7 @@
-kernel.com: *.asm
+default: nbp.com
-	nasm -s -o kernel.com main.asm
+
+%.com: %.asm
+	nasm -s -o $@ $<
 
 clean:
-	rm -f kernel.com
+	rm -f *.com

kernel/heap.asm

@@ -0,0 +1,28 @@
+heap_size:
+  dw 0x0100
+
+heap_init:
+  push ax ; byte value (0)
+  push cx ; loop counter
+  push di ; target ptr
+  xor ax, ax
+  mov cx, [heap_size]
+  mov di, heap
+  rep stosb ; rep makes this loop cx times, incrementing di, writing al
+  pop di
+  pop cx
+  pop ax
+  ret
+
+; in	ax	number of bytes to alloc
+; out	ds:di
+malloc:
+  push dx ; length of block index
+  or ax,0x0F
+  inc ax
+  mov dx, 0x100
+  mov bp, heap
+
+  int 0x2E
+  pop dx
+  ret

nbp.asm

@@ -1,6 +1,6 @@
 ; assumptions about the starting envionment
 cpu 8086
-org 0x0000 ;	if we are not at CS:0000, CS adjustment will fix it for us
+org 0x0000
 ; dl		probable drive number
 ; ds:si		probable pointer to partition structure
 ; es:bx		probable pxeenv+ structure
@@ -42,28 +42,24 @@ _exit:
 main:
   mov ax, cs
   mov ds, ax
+  mov es, ax
 
   mov bx, 0x002E
   mov dx, debug_reg_ir
 
   call ivt_set
 
-  mov ax, 0
+  call heap_init
-  mov bx, 0
+  mov ax, 18
-  call cons
+  call malloc
-  mov si, di
-  call print
 
   ret
 
-%include "intr.asm"
+%include "kernel/heap.asm"
-%include "debug.asm"
+%include "kernel/intr.asm"
-%include "kprintf.asm"
+%include "kernel/debug.asm"
-%include "heap.asm"
+%include "kernel/kprintf.asm"
-
-%include "cons.asm"
-%include "int.asm"
-%include "print.asm"
 
+align 16
 heap:
   dw 0

run.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-exec qemu-system-x86_64 -boot n \
+exec qemu-system-x86_64 -boot n -fda fd0.img \
 	-option-rom /usr/share/qemu/pxe-rtl8139.rom \
 	-device e1000,netdev=mynet0,mac=52:54:00:12:34:56 \
-	-netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.9,tftp=$PWD,bootfile=kernel.com
+	-netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.9,tftp=$PWD,bootfile=nbp.com