1 \documentclass[a4paper, 11pt]{article}
11 \title{Using STM32 discovery kits with open source tools}
12 \author{STLINK development team}
19 \addtocontents{toc}{\protect\setcounter{tocdepth}{1}}
26 This guide details the use of STMicroelectronics STM32 discovery kits in
27 an opensource environment.
32 \section{Installing a GNU toolchain}
34 Any toolchain supporting the cortex m3 should do. You can find the necessary
35 to install such a toolchain here:\\
37 \begin{lstlisting}[frame=tb]
38 https://github.com/esden/summon-arm-toolchain
43 Details for the installation are provided in the topmost README file.
44 This documentation assumes the toolchains is installed in a \$TOOLCHAIN\_PATH.
49 \section{Installing STLINK}
51 STLINK is an opensource software to program and debug the discovery kits. Those
52 kits have an onboard chip that translates USB commands sent by the host PC into
53 JTAG commands. This chip is called STLINK, which is confusing since the software
54 has the same name. It comes into 2 versions (STLINK v1 and v2). From a software
55 point of view, those versions differ only in the transport layer used to communicate
56 (v1 uses SCSI passthru commands, while v2 uses raw USB).
59 Before continuing, the following dependencies are required:
66 The STLINK software source code is retrieved using:\\
68 \begin{lstlisting}[frame=tb]
69 git clone https://github.com/texane/stlink stlink.git
74 Everything can be built from the top directory:\\
76 \begin{lstlisting}[frame=tb]
83 \item a communication library (stlink.git/libstlink.a),
84 \item a GDB server (stlink.git/gdbserver/st-util),
85 \item a flash manipulation tool (stlink.git/flash/flash).
91 \section{Building and running a program}
92 A simple LED blinking example is provided in the example directory. It is built using:\\
94 \begin{lstlisting}[frame=tb]
95 # update the make option accordingly to your architecture
96 cd stlink.git/example/blink ;
97 PATH=$TOOLCHAIN_PATH/bin:$PATH make CONFIG_STM32L_DISCOVERY=1;
102 A GDB server must be start to interact with the STM32. Depending on the discovery kit you
103 are using, you must run one of the 2 commands:\\
105 \begin{lstlisting}[frame=tb]
106 # STM32VL discovery kit
107 $> sudo ./st-util /dev/sg2
109 # STM32L discovery kit
110 # 2 dummy command line arguments needed, will be fixed soon
111 $> sudo ./st-util fu bar
116 Then, GDB can be used to interact with the kit:\\
118 \begin{lstlisting}[frame=tb]
119 $> $TOOLCHAIN_PATH/bin/arm-none-eabi-gdb
124 From GDB, connect to the server using:\\
126 \begin{lstlisting}[frame=tb]
127 $> target extended localhost:4242
132 By default, the program was linked such that the base address is 0x20000000. From the architecture
133 memory map, GDB knows this address belongs to SRAM. To load the program in SRAM, simply use:\\
135 \begin{lstlisting}[frame=tb]
141 GDB automatically set the PC register to the correct value, 0x20000000 in this case. Then, you
142 can run the program using:\\
144 \begin{lstlisting}[frame=tb]
150 The board BLUE and GREEN leds should be blinking (those leds are near the user and reset buttons).
154 \section{Reading and writing to flash}
156 Flash memory reading and writing is done by a separate tool. A binary running in flash is assumed to
157 be linked against address 0x8000000. The flash tool is then used as shown below:\\
159 \begin{lstlisting}[frame=tb]
160 # change to the flash tool directory
161 $> cd stlink.git/flash ;
163 # stlinkv1 command to read 4096 from flash into out.bin
164 $> ./flash read /dev/sg2 out.bin 0x8000000 4096
167 $> ./flash read out.bin 0x8000000 4096
169 # stlinkv1 command to write the file in.bin into flash
170 $> ./flash write /dev/sg2 in.bin 0x8000000
173 $> ./flash write in.bin 0x8000000
181 \subsection{Disassembling THUMB code in GDB}
183 By default, the disassemble command in GDB operates in ARM mode. The programs running on CORTEX-M3
184 are compiled in THUMB mode. To correctly disassemble them under GDB, uses an odd address. For instance,
185 if you want to disassemble the code at 0x20000000, use:\\
187 \begin{lstlisting}[frame=tb]
188 $> disassemble 0x20000001
193 \subsection{libstm32l\_discovery}
195 The repository includes the STM32L discovery library source code from ST original firmware packages,
198 \begin{lstlisting}[frame=tb]
199 http://www.st.com/internet/evalboard/product/250990.jsp#FIRMWARE
206 \begin{lstlisting}[frame=tb]
207 $> cd stlink.git/example/libstm32l_discovery/build
213 An example using the library can be built using:\\
215 \begin{lstlisting}[frame=tb]
216 $> cd stlink.git/example/lcd
224 \item http://www.st.com/internet/mcu/product/248823.jsp\\
225 documentation related to the STM32L mcu
226 \item http://www.st.com/internet/evalboard/product/250990.jsp\\
227 documentation related to the STM32L discovery kit