set $workspace = 0x40000000

define load_usb_firmware
	# load helper
	# lbu r4,(r1+0)
	set *($workspace+0)  = 0x40240000
	# lbu r5,(r1+1)
	set *($workspace+4)  = 0x40250001
	# sli r5,r5,8
	set *($workspace+8)  = 0x3ca50008
	# or r4,r4,r5
	set *($workspace+12)  = 0xb8852000
	# sw (r2+0),r4
	set *($workspace+16)  = 0x58440000
	# addi r1,r1,2
	set *($workspace+20)  = 0x34210002
	# addi r2,r2,4
	set *($workspace+24) = 0x34420004
	# addi r3,r3,-2
	set *($workspace+28) = 0x3463fffe
	# bg r3,r0,-32
	set *($workspace+32) = 0x4860fff8
	# break
	set *($workspace+36) = 0xac000002

	# save registers
	set $saved_r1 = $r1
	set $saved_r2 = $r2
	set $saved_r3 = $r3
	set $saved_r4 = $r4
	set $saved_r5 = $r5
	set $saved_pc = $pc

	restore $arg0 binary $workspace+64
	set $r1 = $workspace+64
	set $r2 = 0xa0000000
	set $r3 = 2048
	jump *($workspace)

	# recall registers
	set $r1 = $saved_r1
	set $r2 = $saved_r2
	set $r3 = $saved_r3
	set $r4 = $saved_r4
	set $r5 = $saved_r5
	set $pc = $saved_pc
end

document load_usb_firmware
	Loads an USB firmware from a binary file.
	Syntax: load_usb_firmware <filename>
end