In addition I can provide the code gcc emits (-save-temps) for
'progname':

	jalr	$25
	nop

	lw	$28,16($fp)
	move	$3,$2
	lw	$2,%got(progname)($28)
	sw	$3,0($2)
	lw	$2,%got(progname)($28)
	lw	$2,0($2)
	move	$4,$2
	lw	$2,%got(startup_hacks)($28)
	addiu	$25,$2,%lo(startup_hacks)
	jalr	$25

and at the end (of main.s):

	.set	macro
	.set	reorder
	.end	get_current_username
	.size	get_current_username, .-get_current_username

	.comm	progname,4,4

	.ident	"GCC: (GNU) 4.1.2 20070110 prerelease (NetBSD nb1 20070110)"

Markus.