kopia lustrzana https://github.com/stlink-org/stlink
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example | ||
gdbserver | ||
nbproject | ||
src | ||
stm32l/src | ||
stm32l_notes | ||
.gitignore | ||
10-stlink.rules | ||
49-stm32l-discovery.rules | ||
AUTHORS | ||
LICENSE | ||
Makefile | ||
README | ||
stlink.modprobe.conf |
README
HOWTO ===== First, load the sg kernel module. # modprobe sg On Ubuntu you need to install the package libsgutils2-dev: # sudo apt-get install libsgutils2-dev 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 Then, in gdb: (gdb) target remote :1234 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:1111 Remote debugging using localhost:1111 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 :1111' is good enough for GDB. Setting up udev rules ===================== For convenience, you may install udev rules file, 10-stlink.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/stlink file, which will point at appropriate /dev/sgX device. Good to not accidentally start debugging your flash drive. Running programs from SRAM ========================== 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 code, if it is linked correctly (i.e. ELF has correct entry point). Writing to flash ================ The GDB stub ships with a correct memory map, including the flash area. If you would link your executable to 0x08000000 and then do (gdb) load firmware.elf then it would be written to the memory. 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'.