default: flash

clean:
	rm -f blob-original blob-1 blob-2 blob-1-hacked blob-hacked

blob-original: boot_usb
	./boot_usb read 0 131072 $@

flash: blob-original blob-hacked boot_usb
	mv blob-original blob-backup-$(shell date +%Y%m%d)
	./boot_usb flash 0 blob-hacked
	./boot_usb off
	rm -f blob-hacked

blob-1: blob-original
	dd if=$< of=$@ bs=1024 count=2

blob-2: blob-original
	dd if=$< of=$@ bs=1024 skip=2

blob-1-hacked: blob-1
	md5="$(firstword $(shell md5sum $<))"; \
	if [ "$$md5" != "4331204d83bb76a6ac06f5bdd32487b5" ]; then \
		exit 1; \
	fi;
	dd if=$< bs=1 count=800 > $@
	# code
	/bin/echo -ne "\xa0\x42\x9f\xe5" >> $@	# ldr r4, [pc, #672]
	/bin/echo -ne "\x00\x50\x94\xe5" >> $@	# ldr r5, [r4]
	/bin/echo -ne "\x00\x50\x84\xe5" >> $@	# str r5, [r4]
	/bin/echo -ne "\x98\x42\x9f\xe5" >> $@	# ldr r4, [pc, #664]
	/bin/echo -ne "\x01\x00\x15\xe3" >> $@	# tst r5, #1
	/bin/echo -ne "\x14\x00\x00\x1a" >> $@	# bne 0x386
	/bin/echo -ne "\x04\x00\x15\xe3" >> $@	# tst r5, #4
	/bin/echo -ne "\x12\x00\x00\x0a" >> $@	# beq 0x386
	/bin/echo -ne "\x7c\x12\x9f\xe5" >> $@	# ldr r1, [pc, #636]
	/bin/echo -ne "\x00\x20\x91\xe5" >> $@	# ldr r2, [r1]
	/bin/echo -ne "\x00\x00\x52\xe3" >> $@	# cmp r2, #0
	/bin/echo -ne "\x00\x00\x00\x0a" >> $@	# beq 0x354
	/bin/echo -ne "\x02\xf0\xa0\xe1" >> $@	# mov pc, r2
	/bin/echo -ne "\x0a\x12\xa0\xe3" >> $@	# mov r1, #0xa0000000
	/bin/echo -ne "\x00\x20\x91\xe5" >> $@	# ldr r2, [r1]
	/bin/echo -ne "\x34\x32\x9f\xe5" >> $@	# ldr r3, [pc, #564]
	/bin/echo -ne "\x03\x00\x52\xe1" >> $@	# cmp r2, r3
	/bin/echo -ne "\x0a\x00\x00\x1a" >> $@	# bne 0x394
	/bin/echo -ne "\x4a\x12\xa0\xe3" >> $@	# mov r1, #0xa0000004
	/bin/echo -ne "\x00\xf0\x91\xe5" >> $@	# ldr pc, [r1]
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x00\x00\xa0\xe1" >> $@	# nop
	/bin/echo -ne "\x0a\x12\xa0\xe3" >> $@	# mov r1, #0xa0000000
	/bin/echo -ne "\x00\x20\x91\xe5" >> $@	# ldr r2, [r1]
	dd if=$< bs=1 skip=916 count=560  >> $@
	# data
	/bin/echo -ne "\x08\x00\xf0\x40" >> $@	# PSPR
	dd if=$< bs=1 skip=1480 >> $@

blob-hacked: blob-1-hacked blob-2
	md5="$(firstword $(shell md5sum blob-1-hacked))"; \
	if [ "$$md5" != "7fa9222673364f477c61e588f2d111ee" ]; then \
		exit 1; \
	fi;
	cat blob-1-hacked blob-2 > blob-hacked
	rm -f blob-1-hacked blob-1 blob-2