\section{Overview}
\paragraph{}
This guide details the use of STMicroelectronics STM32 discovery kits in
-an opensource environment.
+an open source environment.
\newpage
\section{Installing STLINK}
\paragraph{}
-STLINK is an opensource software to program and debug the discovery kits. Those
+STLINK is open source software to program and debug ST's STM32 Discovery kits. Those
kits have an onboard chip that translates USB commands sent by the host PC into
-JTAG commands. This chip is called STLINK, which is confusing since the software
-has the same name. It comes into 2 versions (STLINK v1 and v2). From a software
-point of view, those version differ only in the transport layer used to communicate
-(v1 uses SCSI passthru commands, while v2 uses raw USB).
+JTAG/SWD commands. This chip is called STLINK, (yes, isn't that confusing? suggest a better
+name!) and comes in 2 versions (STLINK v1 and v2). From a software
+point of view, those versions differ only in the transport layer used to communicate
+(v1 uses SCSI passthru commands, while v2 uses raw USB). From a user point of view, they
+are identical.
+
+\paragraph{}
+Before continuing, the following dependencies must be met:
+\begin{itemize}
+\item libusb-1.0
+\item pkg-config
+\item autotools
+\end{itemize}
+
+\paragraph{}
+STLINK should run on any system meeting the above constraints.
+
\paragraph{}
The STLINK software source code is retrieved using:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-git clone https://github.com/texane/stlink stlink.git
+$> git clone https://github.com/texane/stlink stlink.git
\end{lstlisting}
\end{small}
\paragraph{}
-The GDB server is called st-util and is built using:\\
+Everything can be built from the top directory:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> cd stlink.git;
-$> make ;
-$> cd gdbserver ;
-$> make ;
+$> cd stlink.git
+$> ./autogen.sh
+$> ./configure
+$> make
\end{lstlisting}
\end{small}
+It includes:
+\begin{itemize}
+\item a communication library (stlink.git/libstlink.a),
+\item a GDB server (stlink.git/st-util),
+\item a flash manipulation tool (stlink.git/st-flash).
+\end{itemize}
\newpage
+\section{Using the GDB server}
+\paragraph{}
+This assumes you have got the libopencm3 project downloaded in [ocm3]. The
+libopencm3 project has some good, reliable examples for each of the Discovery boards.
+
+Even if you don't plan on using libopencm3, the examples they provide will help you
+verify that:
-\section{Building and running a program}
-A simple LED blinking example is provided in the example directory. It is built using:\\
+\begin{itemize}
+\item Your installed toolchain is capable of compiling for cortex M3/M4 targets
+\item stlink is functional
+\item Your arm-none-eabi-gdb is functional
+\item Your board is functional
+\end{itemize}
+
+\paragraph{}
+A GDB server must be started to interact with the STM32. Depending on the discovery kit you
+are using, you must run one of the 2 commands:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-cd stlink.git/example ;
-PATH=$TOOLCHAIN_PATH/bin:$PATH make ;
+# STM32VL discovery kit (onboard ST-link)
+$> ./st-util --stlinkv1
+
+# STM32L or STM32F4 discovery kit (onboard ST-link/V2)
+$> ./st-util
+
+# Full help for other options (listen port, version)
+$> ./st-util --help
\end{lstlisting}
\end{small}
\paragraph{}
-A GDB server must be start to interact with the STM32.
-Depending on the discovery kit you are using, you must
-run one of the 2 commands:\\
+Then, GDB can be used to interact with the kit:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-# STM32VL discovery kit
-$> sudo ./st-util /dev/sg2
+$> $TOOLCHAIN_PATH/bin/arm-none-eabi-gdb example_file.elf
+\end{lstlisting}
+\end{small}
-# STM32L discovery kit
-$> sudo ./st-util
+\paragraph{}
+From GDB, connect to the server using:\\
+\begin{small}
+\begin{lstlisting}[frame=tb]
+(gdb) target extended localhost:4242
\end{lstlisting}
\end{small}
\paragraph{}
-Then, GDB can be used to interact with the kit:\\
+GDB has memory maps for as many chips as it knows about, and will load your project
+into either flash or SRAM based on how the project was linked. Linking projects
+to boot from SRAM is beyond the scope of this document.
+
+Because of these built in memory maps, after specifying the .elf at the command line, now
+we can simply "load" the target:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> $TOOLCHAIN_PATH/bin/arm-none-eabi-gdb
+(gdb) load
\end{lstlisting}
\end{small}
\paragraph{}
-From GDB, connect to the server using:\\
+st-util will load all sections into their appropriate addresses, and "correctly" set the PC
+register. So, to run your freshly loaded program, simply "continue"\\
+\begin{small}
+\begin{lstlisting}[frame=tb]
+(gdb) continue
+\end{lstlisting}
+\end{small}
+
+\paragraph{}
+Your program should now be running, and, if you used one of the blinking examples from
+libopencm3, the LEDs on the board should be blinking for you.
+
+\newpage
+\section{Building and flashing a program}
+\paragraph{}
+If you want to simply flash binary files to arbitrary sections of memory, or
+read arbitary addresses of memory out to a binary file, use the st-flash tool,
+as shown below:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> target extended localhost:4242
+
+# stlinkv1 command to read 4096 from flash into out.bin
+$> ./st-flash read v1 out.bin 0x8000000 4096
+
+# stlinkv2 command
+$> ./st-flash read out.bin 0x8000000 4096
+
+# stlinkv1 command to write the file in.bin into flash
+$> ./st-flash write v1 in.bin 0x8000000
+
+# stlinkv2 command
+$> ./st-flash write in.bin 0x8000000
\end{lstlisting}
\end{small}
\paragraph{}
-To load the program, use:\\
+Of course, you can use this instead of the gdb server, if you prefer. Just remember
+to use the ".bin" image, rather than the .elf file.\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> load blink.elf
+
+# write blink.bin into FLASH
+$> [sudo] ./st-flash write fancy_blink.bin 0x08000000
\end{lstlisting}
\end{small}
\paragraph{}
-Then, you can run the program using:\\
+Upon reset, the board LEDs should be blinking.
+
+\newpage
+\section{Notes}
+
+\subsection{Disassembling THUMB code in GDB}
+\paragraph{}
+By default, the disassemble command in GDB operates in ARM mode. The programs running on CORTEX-M3
+are compiled in THUMB mode. To correctly disassemble them under GDB, uses an odd address. For instance,
+if you want to disassemble the code at 0x20000000, use:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> run
+(gdb) disassemble 0x20000001
\end{lstlisting}
\end{small}
documentation related to the STM32L mcu
\item http://www.st.com/internet/evalboard/product/250990.jsp\\
documentation related to the STM32L discovery kit
+\item http://www.libopencm3.org\\
+ libopencm3, a project providing a firmware library, with solid examples for Cortex
+ M3, M4 and M0 processors from any vendor.
\end{itemize}
\end{document}
projects / fw / stlink / blobdiff