Merge "[firmware] add missing knock-knock code"
diff --git a/hardware/eraser.asm b/hardware/eraser.asm
new file mode 100644
index 0000000..f0a2311
--- /dev/null
+++ b/hardware/eraser.asm
@@ -0,0 +1,101 @@
+;
+; Copyright (C) 2012 The Android Open Source Project
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+; http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+
+; ADK2 Sam3X Eraser Controller
+; Author: Fuller
+
+; serial DTR line as clock on GP0
+; serial RTS line as data on GP1
+; GP2 output controls Sam3X erase feature
+; GP0, input, /DTR
+; GP1, input, /RTS
+; GP2, output, erase
+; GP3, input, internal pull-up, floating
+
+ #include "P10F200.INC"
+; configuration bits
+ __CONFIG (_WDT_OFF&_CP_ON&_MCLRE_OFF)
+
+; memory map
+; only 16 bytes of RAM starting at 0x10
+ udata
+GPIO_sampled res 1
+GPIO_sampledQ res 1
+magicKeyL res 1
+magicKeyH res 1
+tick0 res 1
+tick1 res 1
+
+ code 0x00
+; initialize microcontroller
+ movlw (1<<NOT_GPWU|1<<PS2|1<<PS1|1<<PS0) ; no wake up, pull-ups
+ ; TMR0 at 1:256 for low power
+ option
+ bcf GPIO, GP2
+ movlw (1<<GP3|1<<GP1|1<<GP0) ; GP2 is only output
+ tris GPIO
+
+; initialize variables
+ clrf magicKeyH
+ clrf magicKeyL
+ bsf GPIO_sampled, GP0 ; can't get false rise if assume high
+
+sampler:
+ movf GPIO_sampled, W ; old stale sample
+ movwf GPIO_sampledQ ; clock pipe for edge detection
+ movf GPIO, W ; fresh sample
+ movwf GPIO_sampled ; sampled copy of IO's
+; check for rising clock edge
+ btfss GPIO_sampled, GP0
+ goto sampler ; if not set, then it's not rising
+ btfsc GPIO_sampledQ, GP0 ; if old is clear, then rising
+ goto sampler
+
+shifter:
+ movf GPIO, W ; sample the data
+ movwf GPIO_sampledQ ; reuse the same memory location
+ btfss GPIO_sampledQ, GP0
+ goto sampler ; if clock has already dropped, abort
+ bsf STATUS, C
+ btfss GPIO_sampledQ, GP1 ; sets C to match GP1 for shift in
+ bcf STATUS, C
+ rrf magicKeyH ; first half of..
+ rrf magicKeyL ; 16-bit shift through C
+ movlw 0xac
+ subwf magicKeyH, W
+ btfss STATUS, Z ; check for key-pattern match
+ goto sampler
+ movlw 0x5a
+ subwf magicKeyL, W
+ btfss STATUS, Z ; check for key-pattern match
+ goto sampler
+erase:
+; begin erase trigger
+ bsf GPIO, GP2
+; delay for erase trigger period, estimate 393mS for this code...
+delay:
+ clrf tick0
+ clrf tick1
+delayLoop:
+; inc16
+ incf tick0
+ btfsc STATUS, Z
+ incf tick1
+ btfss STATUS, Z
+ goto delayLoop
+; end erase trigger
+ bcf GPIO, GP2
+ goto sampler
+ end
diff --git a/hardware/eraser.hex b/hardware/eraser.hex
new file mode 100644
index 0000000..586f178
--- /dev/null
+++ b/hardware/eraser.hex
@@ -0,0 +1,10 @@
+:020000040000FA
+:10000000870C020046040B0C0600730072001005FA
+:1000100010023100060230001007080A1106080A13
+:10002000060231001107080A0305310703043303F0
+:100030003203AC0C93004307080A5A0C92004307A2
+:10004000080A460574007500B4024306B50243076A
+:06005000240A4604080A20
+:040056000008000896
+:021FFE00E30FEF
+:00000001FF
