+IMPORTANT SHORT TERM NOTICE:
+If you are targetting F1 devices, with either stlinkv1 or v2 hardware, you
+_need_ to use karlp's libwork2 branch.
+
+If you are targetting F4, you _need_ to use texane's master
+
+If you are targetting F2 or L1, please let us know how it goes!
+
HOWTO
=====
-To run the gdb server, do (you do not need sudo if you have
-set up permissions correctly):
-$ make -C build && sudo ./build/st-util 1234 /dev/sg1
+First, you have to know there are several boards supported by the software.
+Those boards use a chip to translate from USB to JTAG commands. The chip is
+called stlink and there are 2 versions:
+. STLINKv1, present on STM32VL discovery kits,
+. STLINKv2, present on STM32L discovery and later kits.
+
+2 different transport layers are used:
+. STLINKv1 uses SCSI passthru commands over USB,
+. STLINKv2 uses raw USB commands.
+
+Common requirements
+~~~~~~~~~~~~~~~~~~~
+
+libusb-1.0 (You probably already have this, but you'll need the
+development version to compile)
+
+IF YOU HAVE AN STLINKv1
+~~~~~~~~~~~~~~~~~~~~~~~
+The STLINKv1's SCSI emulation is very broken, so the best thing to do
+is tell your operating system to completely ignore it.
+
+Options (do one of these before you plug it in)
+ *) modprobe -r usb-storage && modprobe usb-storage quirks=483:3744:i
+or *)1. add "options usb-storage quirks=483:3744:i" to /etc/modprobe.conf
+ *)2. modprobe -r usb-storage && modprobe usb-storage
+or *)1. cp stlink_v1.modprobe.conf /etc/modprobe.d
+ *)2. modprobe -r usb-storage && modprobe usb-storage
-Then, in gdb:
-(gdb) target remote :1234
+IF YOU HAVE AN STLINKv2
+~~~~~~~~~~~~~~~~~~~~~~~
+
+You're ready to go :)
+
+To run the gdb server, do (you do not need sudo if you have set up
+permissions correctly):
+$ make && [sudo] ./gdbserver/st-util
+
+There are a few options:
+
+./gdbserver/st-util - usage:
+
+ -h, --help Print this help
+ -vXX, --verbose=XX specify a specific verbosity level (0..99)
+ -v, --verbose specify generally verbose logging
+ -s X, --stlink_version=X
+ Choose what version of stlink to use, (defaults to 2)
+ -1, --stlinkv1 Force stlink version 1
+ -p 4242, --listen_port=1234
+ Set the gdb server listen port. (default port: 4242)
+
+Then, in gdb: (remember, you need to run an _ARM_ gdb, not an x86 gdb)
+(gdb) target remote :4242
Have fun!
+Resetting the chip from GDB
+===========================
+
+You may reset the chip using GDB if you want. You'll need to use `target
+extended-remote' command like in this session:
+(gdb) target extended-remote localhost:4242
+Remote debugging using localhost:4242
+0x080007a8 in _startup ()
+(gdb) kill
+Kill the program being debugged? (y or n) y
+(gdb) run
+Starting program: /home/whitequark/ST/apps/bally/firmware.elf
+
+Remember that you can shorten the commands. `tar ext :4242' is good enough
+for GDB.
+
+Setting up udev rules
+=====================
+
+For convenience, you may install udev rules file, 49-stlinkv*.rules, located
+in the root of repository. You will need to copy it to /etc/udev/rules.d,
+and then either reboot or execute
+$ udevadm control --reload-rules
+
+Udev will now create a /dev/stlinkv2_XX or /dev/stlinkv1_XX file, with the appropriate permissions.
+This is currently all the device is for, (only one stlink of each version is supported at
+any time presently)
+
Running programs from SRAM
==========================
-You can run your firmware directly from SRAM if you want to.
-Just link it at 0x20000000 and do
+You can run your firmware directly from SRAM if you want to. Just link
+it at 0x20000000 and do
(gdb) load firmware.elf
It will be loaded, and pc will be adjusted to point to start of the
(gdb) load firmware.elf
then it would be written to the memory.
-Caveats
-=======
-`continue' GDB command does not work: target does not step at
-all or steps with a turtle speed. Looks like there's something
-wrong with SCSI requests.
+FAQ
+===
+
+Q: My breakpoints do not work at all or only work once.
+
+A: Optimizations can cause severe instruction reordering. For example,
+if you are doing something like `REG = 0x100;' in a loop, the code may
+be split into two parts: loading 0x100 into some intermediate register
+and moving that value to REG. When you set up a breakpoint, GDB will
+hook to the first instruction, which may be called only once if there are
+enough unused registers. In my experience, -O3 causes that frequently.
+
+Q: At some point I use GDB command `next', and it hangs.
+
+A: Sometimes when you will try to use GDB `next' command to skip a loop,
+it will use a rather inefficient single-stepping way of doing that.
+Set up a breakpoint manually in that case and do `continue'.
+
+Currently known working combinations of programmer and target
+=============================================================
+
+STLink v1 (as found on the 32VL Discovery board)
+
+Known Working Targets:
+* STM32F100xx (Medium Density VL)
+* STM32F103 (according to jpa- o n##stm32
+
+No information:
+* everything else!
+
+
+STLink v2 (as found on the 32L and F4 Discovery boards)
+Known Working Targets:
+* STM32F100xx (Medium Density VL, as on the 32VL Discovery board)
+* ?
-GDB sends requests for a multi-sectioned ELF files (most ones;
-having both .text and .rodata is enough) in a quite strange way which
-absolutely does not conform to flash page boundaries. Which is even more
-weird when you think about FlashErase requests which it sends correctly.
-And I couldn't think of a way which will resolve this correctly now.
+Please report any and all known working combinations so I can update this!
-Hardware breakpoints are not supported yet. You can still run your code from
-RAM, and then GDB will insert bkpt opcodes automagically.
projects / fw / stlink / blobdiff