firmware: Start fastflash when left button held

firmware/Makefile

@@ -1,4 +1,11 @@
+ifeq ($(FASTFLASH),1)
+APPVER = 2.0.0
+
+OBJS += fastflash.o
+OBJS += bootloader.o
+else
 APPVER = 1.0.0
+endif
 
 NAME  = trezor
 
@@ -59,6 +66,10 @@ OBJS += protob/types.pb.o
 
 include ../Makefile.include
 
+ifeq ($(FASTFLASH),1)
+CFLAGS += -DFASTFLASH
+endif
+
 CFLAGS += -Wno-sequence-point
 CFLAGS += -Iprotob -DPB_FIELD_16BIT=1
 CFLAGS += -DQR_MAX_VERSION=0

firmware/fastflash.c

@@ -0,0 +1,47 @@
+/*
+ * This file is part of the TREZOR project.
+ *
+ * Copyright (C) 2017 Saleem Rashid <trezor@saleemrashid.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "fastflash.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <libopencm3/cm3/scb.h>
+
+extern uint32_t __bootloader_loadaddr__[];
+extern uint32_t __bootloader_runaddr__[];
+extern uint8_t __bootloader_size__[];
+
+void load_bootloader() {
+	memcpy(__bootloader_runaddr__, __bootloader_loadaddr__, (size_t) __bootloader_size__);
+}
+
+void run_bootloader() {
+	// Relocate vector tables
+	SCB_VTOR = (uint32_t) __bootloader_runaddr__;
+
+	// Set stack pointer
+	__asm__ volatile("msr msp, %0":: "r" (__bootloader_runaddr__[0]));
+
+	// Jump to address
+	((void (*)(void))(__bootloader_runaddr__[1]))();
+
+	while (true);
+}

firmware/fastflash.h

@@ -0,0 +1,26 @@
+/*
+ * This file is part of the TREZOR project.
+ *
+ * Copyright (C) 2017 Saleem Rashid <trezor@saleemrashid.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __FASTFLASH_H__
+#define __FASTFLASH_H__
+
+void load_bootloader(void);
+void __attribute__((noreturn)) run_bootloader(void);
+
+#endif

firmware/trezor.c

@@ -29,6 +29,7 @@
 #include "rng.h"
 #include "timer.h"
 #include "buttons.h"
+#include "fastflash.h"
 
 uint32_t __stack_chk_guard;
 
@@ -98,6 +99,14 @@ int main(void)
 	__stack_chk_guard = random32(); // this supports compiler provided unpredictable stack protection checks
 #endif
 
+#if FASTFLASH
+	uint16_t state = gpio_port_read(BTN_PORT);
+	if ((state & BTN_PIN_NO) == 0) {
+		load_bootloader();
+		run_bootloader();
+	}
+#endif
+
 	timer_init();
 
 #if DEBUG_LINK

memory_app_2.0.0.ld

@@ -0,0 +1,21 @@
+/* STM32F205RE - 512K Flash, 128K RAM */
+/* program starts at 0x08010000 */
+MEMORY
+{
+	rom (rx)        : ORIGIN = 0x08010000, LENGTH = 512K - 64K
+	bootloader (rx) : ORIGIN = 0x20000000, LENGTH = __bootloader_size__
+	ram (rwx)       : ORIGIN = ORIGIN(bootloader) + LENGTH(bootloader),
+			  LENGTH = 128K - LENGTH(bootloader)
+}
+
+INCLUDE libopencm3_stm32f2.ld
+
+SECTIONS
+{
+	.bootloader : {
+		__bootloader_runaddr__ = .;
+		KEEP (*(.bootloader*))
+	} >bootloader AT >rom
+
+	__bootloader_loadaddr__ = LOADADDR(.bootloader);
+}