firmware-reversing

OpenGDB + GDB

• Install the latest version of OpenOCD

git clone http://openocd.zylin.com/openocd
cd openocd
./bootstrap
./configure
make -j4
sudo make install

• Run OpenOCD and dump the memory

cd $THIS_REPO
openocd -f res/ftdi.cfg -f res/efm32.cfg

# In another terminal

telnet localhost 4444

flash read_bank 0 dump.bin

• Debug with gdb

arm-none-eabi-gdb

(gbd) target remote localhost:3333
(gdb) monitor reset halt

Useful info

Memory map

• ROM: 0x00000000 - 0x00040000 (256kB)

• RAM: 0x20000000 - 0x20007fff (32kB)

• Peripherals:

  • ACMP0: 0x40000000 - 0x400003ff
  • ACMP1: 0x40000400 - 0x400007ff
  • ADC0: 0x40002000 - 0x400023ff
  • IDAC0: 0x40006000 - 0x400063ff
  • GPIO: 0x4000a000 - 0x4000afff
  • I2C0: 0x4000c000 - 0x4000c3ff
  • USART0: 0x40010000 - 0x400103ff
  • USART1: 0x40010400 - 0x400107ff
  • TIMER0: 0x40018000 - 0x400183ff
  • TIMER1: 0x40018400 - 0x400187ff
  • GPCRC: 0x4001c000 - 0x4001c3ff
  • CRYOTIMER: 0x4001e000 - 0x4001e3ff
  • RTCC: 0x40042000 - 0x400423ff
  • LETIMER0: 0x40046000 - 0x400463ff

• ARM Vector table