__guard:    .space 200

__store_GP: .word 0
__store_SP: .word 0
__store_FP: .word 0

__chr_Reg:  .asciiz "Register save mask (should be 0, {$gp, $sp, $fp, $s7-0}): "
__chr_Tild: .asciiz "Number of '\\0's rewritten to '~': "
__chr_Char: .asciiz "Number of characters printed: "
__chr_Hash: .asciiz "#"
__chr_Line: .asciiz "\n"
__chr_PGF:  .asciiz "Pre-guard overwritten\n"
__chr_PGO:  .asciiz "Pre-guard okay\n"
__chr_AGF:  .asciiz "After-guard overwritten\n"
__chr_AGO:  .asciiz "After-guard okay\n"

	.text
__start:
	# Set up guard values in the buffer
	la	$t0, __MIPSCALL_arg0
	la	$t1, __MIPSCALL_arg0_end
	li	$t2, '*'
__initloop:
	sb	$t2, 0($t0)
	addiu	$t0, $t0, 1
	bne	$t0, $t1, __initloop
 

	# Save the preserved pointer registers
	la	$t0, __store_GP
	sw	$gp, 0($t0)
	la	$t0, __store_SP
	sw	$sp, 0($t0)
	la	$t0, __store_FP
	sw	$fp, 0($t0)
	
	# Put fixed values in all the non-saved registers (to check that sutdents initialize their registers properly)
	li	$at, 0xC0ED0000
	li	$v0, 0xC0ED1111
	li	$v1, 0xC0ED2222
	li	$a0, 0xC0ED3333
	li	$a1, 0xC0ED4444
	li	$a2, 0xC0ED5555
	li	$a3, 0xC0ED6666
	li	$t0, 0xC0ED7777
	li	$t1, 0xC0ED8888
	li	$t2, 0xC0ED9999
	li	$t3, 0xC0EDAAAA
	li	$t4, 0xC0EDBBBB
	li	$t5, 0xC0EDCCCC
	li	$t6, 0xC0EDDDDD
	li	$t7, 0xC0EDEEEE
	li	$t8, 0xC0EDFFFF
	li	$t9, 0xC0ED1010
	li	$k0, 0xC0ED1111
	li	$k1, 0xC0ED1212

	# Put fixed values in the save registers
	li	$s0, 0x57AB0000
	li	$s1, 0x57AB1111
	li	$s2, 0x57AB2222
	li	$s3, 0x57AB3333
	li	$s4, 0x57AB4444
	li	$s5, 0x57AB5555
	li	$s6, 0x57AB6666
	li	$s7, 0x57AB7777

	# Put fixed values in all the non-saved registers (to check that sutdents initialize their registers properly)
	li	$at, 0xC0ED0000