Removed comment about STM32F4 limitations

[fw/stlink] / README

diff --git a/README b/README
index 920786ebf407b57d062bafbfbba5ac5484630004..f85c6815a5cddf5741afdb750f1b8dec8d5e7e10 100644 (file)
--- a/README
+++ b/README
@@ -1,12 +1,33 @@
 HOWTO
 =====
 
+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.
+
+It means that if you are using a STM32VL board, you have to install and load
+SCSI related software. First, load the sg kernel module:
+# modprobe sg
+
+Then, you need to install the package libsgutils2-dev. On Ubuntu:
+# sudo apt-get install libsgutils2-dev
+
+LIBUSB is required for both cases.
+
 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
+$ make -C build && sudo ./build/st-util [/dev/sgX]
+
+Currently, the GDB server listening port is hardcoded to 4242:
 
 Then, in gdb:
-(gdb) target remote :1234
+(gdb) target remote :4242
 
 Have fun!
 
@@ -15,17 +36,28 @@ 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
+(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 :1111' is good enough
+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, 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
 ==========================
 
@@ -44,6 +76,7 @@ If you would link your executable to 0x08000000 and then do
 (gdb) load firmware.elf
 then it would be written to the memory.
 
+
 FAQ
 ===