Add null driver

This will be the target of our real ELF loader

assets/initrd.manifest

@@ -1 +1,2 @@
-assets/fonts/tamsyn8x16r.psf screenfont.psf
+#assets/fonts/tamsyn8x16r.psf screenfont.psf
+build/kernel/src/drivers/nulldrv/nulldrv nulldrv

src/drivers/nulldrv/main.cpp

@@ -0,0 +1 @@
+int main(int argc, const char **argv) { return 0; }

src/drivers/nulldrv/main.s

@@ -0,0 +1,11 @@
+global _start
+_start:
+	xor rbp, rbp	; Sentinel rbp
+
+	pop rsi			; My PID
+	mov rdi, 0		; DEBUG syscall
+
+.loop:
+	syscall
+	jmp .loop
+

src/drivers/nulldrv/wscript

@@ -0,0 +1,15 @@
+
+def configure(ctx):
+    pass
+
+def build(bld):
+    sources = bld.path.ant_glob("**/*.cpp")
+    sources += bld.path.ant_glob("**/*.s")
+
+    bld.program(
+        source = sources,
+        name = 'nulldrv',
+        target = 'nulldrv',
+    )
+
+# vim: ft=python et