\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
+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).
+(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 libsgutils2 (optionnal)
+\item pkg-config
+\item autotools
\end{itemize}
\paragraph{}
\begin{small}
\begin{lstlisting}[frame=tb]
$> cd stlink.git
-$> make CONFIG_USE_LIBSG=0
+$> ./autogen.sh
+$> ./configure
+$> make
\end{lstlisting}
\end{small}
It includes:
\begin{itemize}
\item a communication library (stlink.git/libstlink.a),
-\item a GDB server (stlink.git/gdbserver/st-util),
-\item a flash manipulation tool (stlink.git/flash/flash).
+\item a GDB server (stlink.git/st-util),
+\item a flash manipulation tool (stlink.git/st-flash).
\end{itemize}
\newpage
+\section{Using the GDB server}
+\paragraph{}
+This assumes you have got the libopencm3 project downloaded in [ocm3]. The
+libopencm3 project has some good, reliable examples for each of the Discovery boards.
-\section{Building and running a program}
-A simple LED blinking example is provided in the example directory. It is built using:\\
-\begin{small}
-\begin{lstlisting}[frame=tb]
-# update the make option accordingly to your architecture
-cd stlink.git/example/blink ;
-PATH=$TOOLCHAIN_PATH/bin:$PATH make CONFIG_STM32L_DISCOVERY=1;
-\end{lstlisting}
-\end{small}
+Even if you don't plan on using libopencm3, the examples they provide will help you
+verify that:
+
+\begin{itemize}
+\item Your installed toolchain is capable of compiling for cortex M3/M4 targets
+\item stlink is functional
+\item Your arm-none-eabi-gdb is functional
+\item Your board is functional
+\end{itemize}
\paragraph{}
-A GDB server must be start to interact with the STM32. Depending on the discovery kit you
+A GDB server must be started to interact with the STM32. Depending on the discovery kit you
are using, you must run one of the 2 commands:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-# STM32VL discovery kit
-$> sudo ./st-util /dev/sg2
+# STM32VL discovery kit (onboard ST-link)
+$> ./st-util --stlinkv1
-# STM32L discovery kit
-# 2 dummy command line arguments needed, will be fixed soon
-$> sudo ./st-util fu bar
+# 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}
Then, GDB can be used to interact with the kit:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> $TOOLCHAIN_PATH/bin/arm-none-eabi-gdb
+$> $TOOLCHAIN_PATH/bin/arm-none-eabi-gdb example_file.elf
\end{lstlisting}
\end{small}
From GDB, connect to the server using:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> target extended localhost:4242
+(gdb) target extended localhost:4242
\end{lstlisting}
\end{small}
\paragraph{}
-By default, the program was linked such that the base address is 0x20000000. From the architecture
-memory map, GDB knows this address belongs to SRAM. To load the program in SRAM, simply use:\\
+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]
-$> load blink.elf
+(gdb) load
\end{lstlisting}
\end{small}
\paragraph{}
-GDB automatically set the PC register to the correct value, 0x20000000 in this case. Then, you
-can run the program using:\\
+st-util will load all sections into their appropriate addresses, and "correctly" set the PC
+register. So, to run your freshly loaded program, simply "continue"\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> continue
+(gdb) continue
\end{lstlisting}
\end{small}
\paragraph{}
-The board BLUE and GREEN leds should be blinking (those leds are near the user and reset buttons).
-
+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{Reading and writing to flash}
+\section{Building and flashing a program}
\paragraph{}
-Flash memory reading and writing is done by a separate tool. A binary running in flash is assumed to
-be linked against address 0x8000000. The flash tool is then used as shown below:\\
+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]
-# change to the flash tool directory
-$> cd stlink.git/flash ;
# stlinkv1 command to read 4096 from flash into out.bin
-$> ./flash read /dev/sg2 out.bin 0x8000000 4096
+$> ./st-flash read v1 out.bin 0x8000000 4096
# stlinkv2 command
-$> ./flash read out.bin 0x8000000 4096
+$> ./st-flash read out.bin 0x8000000 4096
# stlinkv1 command to write the file in.bin into flash
-$> ./flash write /dev/sg2 in.bin 0x8000000
+$> ./st-flash write v1 in.bin 0x8000000
# stlinkv2 command
-$> ./flash write in.bin 0x8000000
+$> ./st-flash write in.bin 0x8000000
\end{lstlisting}
\end{small}
-
-\newpage
-\section{Building and installing the CHIBIOS kernel}
-\paragraph{}
-CHIBIOS is an open source RTOS. More information can be found on the project website:
-\begin{center}
-http://www.chibios.org/dokuwiki/doku.php
-\end{center}
-
-\paragraph{}
-It supports several boards, including the STM32L DISCOVERY kit:
-\begin{center}
-http://www.chibios.org/dokuwiki/doku.php?id=chibios:articles:stm32l\_discovery
-\end{center}
-
\paragraph{}
-The installation procedure is detailed below:\\
+Of course, you can use this instead of the gdb server, if you prefer. Just remember
+to use the ".bin" image, rather than the .elf file.\\
\begin{small}
\begin{lstlisting}[frame=tb]
-# checkout and build CHIBIOS for STM32L DISCOVERY kits
-svn checkout https://chibios.svn.sourceforge.net/svnroot/chibios/trunk
-cd chibios/trunk/demos/ARMCM3-STM32L152-DISCOVERY
-PATH=$TOOLCHAIN_PATH:$PATH make
-# flash the image into STM32L
-sudo ./flash write build/ch.bin 0x08000000
+# write blink.bin into FLASH
+$> [sudo] ./st-flash write fancy_blink.bin 0x08000000
\end{lstlisting}
\end{small}
+\paragraph{}
+Upon reset, the board LEDs should be blinking.
+
\newpage
\section{Notes}
if you want to disassemble the code at 0x20000000, use:\\
\begin{small}
\begin{lstlisting}[frame=tb]
-$> disassemble 0x20000001
-\end{lstlisting}
-\end{small}
-
-
-\subsection{libstm32l\_discovery}
-\paragraph{}
-The repository includes the STM32L discovery library source code from ST original firmware packages,
-available here:\\
-\begin{small}
-\begin{lstlisting}[frame=tb]
-http://www.st.com/internet/evalboard/product/250990.jsp#FIRMWARE
-\end{lstlisting}
-\end{small}
-
-\paragraph{}
-It is built using:\\
-\begin{small}
-\begin{lstlisting}[frame=tb]
-$> cd stlink.git/example/libstm32l_discovery/build
-$> make
-\end{lstlisting}
-\end{small}
-
-\paragraph{}
-An example using the library can be built using:\\
-\begin{small}
-\begin{lstlisting}[frame=tb]
-$> cd stlink.git/example/lcd
-$> make
-\end{lstlisting}
-\end{small}
-
-\subsection{STM32VL support}
-\paragraph{}
-It seems support for STM32VL is quite broken. If it does not work, try build STLINK using libsg:
-\begin{small}
-\begin{lstlisting}[frame=tb]
-$> cd stlink.git
-$> make CONFIG_USE_LIBSG=1
+(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}