opt: add directory; add asm demo

base/opt/asm-demo.s

@@ -0,0 +1,23 @@
+# x86 Assembly w/ libc
+.global fprintf # libc export
+.global stdout  # libc export
+
+.global main # our exported main function, called by C runtime
+
+main:
+	push $world
+	push $hello
+	push stdout
+	call fprintf # fprintf(stdout, "Hello, %s!\n", "world");
+	pop %eax
+	pop %eax
+	pop %eax
+
+	mov $0, %eax
+	ret
+
+hello:
+	.asciz "Hello, %s!\n"
+
+world:
+	.asciz "world"

base/opt/build.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+export CRTBEG="/lib/crt0.o /lib/crti.o /usr/lib/crtbegin.o"
+export CRTEND="/usr/lib/crtend.o /lib/crtn.o"
+
+/usr/i686-pc-toaru/bin/as -o /tmp/asm-demo.o asm-demo.s
+/usr/i686-pc-toaru/bin/ld -o /tmp/asm-demo $CRTBEG -lc /tmp/asm-demo.o $CRTEND