I am looking for assistance with the proper GDB / OpenOCD initializion and running commands (external tools) to use within Eclipse for flash and RAM debugging, as well as the proper modifications or additions that need to be incorporated in a makefile for flash vs RAM building for this MCU, if this matters of course.
MCU: STM32F103VET6
I am using Eclipse Helios with Zylin Embedded CDT, Yagarto Tools and Bins, OpenOCD 0.4, and have an Olimex ARM-USB-OCD JTAG adapter.
I have already configured the ARM-USB-OCD and added it as an external tool in Eclipse. For initializing OpenOCD I used the following command in Eclipse. The board config file references the stm32 MCU:
openocd -f interface/olimex-arm-usb-ocd-h.cfg -f board/stm32f10x_128k_eval.cfg
When I run this within Eclipse everything appears to be working (GDB Interface, OpenOCD finds the MCU, etc). I can also telnet into OpenOCD and run commands.
So, I am stuck on the next part; initialization and commands for flash and RAM debugging, as well as erasing flash.
I read through several tutorials, and scoured the net, but have not been able to find anything particular to this processor. I am new to this, so I might not be recognizing an equivalent product for an example.
I'm working with the same tool chain to program and debug a STM32F107 board. Following are my observations to get an STM32Fxxx chip programmed and debugged under this toolchain.
Initial Starting Point
So at this point you've got a working OpenOCD to ARM-USB-OCD connection and so you should be all set on that end. Now the work is on getting Eclipse/Zylin/Yagarto GDB combination to properly talk to the STM32Fxxx through the OpenOCD/Olimex connection. One thing to keep in mind is that all the OpenOCD commands to issue are the run mode commands. The configuration scripts and command-line options to invoke the OpenOCD server are configuration mode commands. Once you issue the init command then the server enters run mode which opens up the set of commands you'll need next. You've probably done it somewhere else but I tack on a '-c "init"' option when I call the OpenOCD server like so:
openocd -f /path to scripts/olimex-arm-usb-ocd-h.cfg -f /path to targets/stm32f107.cfg -c "init"
The following commands I issue next are done by the Eclipse Debug Configurations dialogue. Under the Zylin Embedded debug (Native) section, I create a new configuration, give it a name, Project (optional), and absolute path to the binary that I want to program. Under the Debugger tab I set the debugger to Embedded GDB, point to the Yagarto GDB binary path, don't set a GDB command file, set GDB command set to Standard, and the protocol to mi.
The Commands Tab - Connect GDB to OpenOCD
So the next tab is the Commands tab and that's where the meat of the issue lies. You have two spaces Initialize and Run. Not sure exactly what the difference is except to guess that they occur pre- and post-invocation of GDB. Either way I haven't noticed a difference in how my commands are run.
But anyway, following the examples I found on the net, I filled the Initialize box with the following commands:
set remote hardware-breakpoint limit 6
set remote hardware-watchoint-limit 4
target remote localhost:3333
monitor halt
monitor poll
First two lines tell GDB how many breakpoints and watchpoints you have. Open OCD Manual Section 20.3 says GDB can't query for that information so I tell it myself. Next line commands GDB to connect to the remote target at the localhost over port 3333. The last line is a monitor command which tells GDB to pass the command on to the target without taking any action itself. In this case the target is OpenOCD and I'm giving it the command halt. After that I tell OpenOCD to switch to asynchronous mode of operation. As some of the following operations take a while, it's useful not to have OpenOCD block and wait for every operation.
Sidenote #1: If you're ever in doubt about the state of GDB or OpenOCD then you can use the Eclipse debug console to send commands to GDB or OpenOCD (via GDB monitor commands) after invoking this debug configuration.
The Commands Tab - Setting up the User Flash
Next are commands I give in the Run commands section:
monitor flash probe 0
monitor flash protect 0 0 127 off
monitor reset halt
monitor stm32x mass_erase 0
monitor flash write_image STM3210CTest/test_rom.elf
monitor flash protect 0 0 127 on
disconnect
target remote localhost:3333
monitor soft_reset_halt
to be explained in the following sections...
Setting up Access to User Flash Memory
First I issue an OpenOCD query to see if it can find the flash module and report the proper address. If it responds that it found the flash at address 0x08000000 then we're good. The 0 at the end specifies to get information about flash bank 0.
Sidenote #2: The STM32Fxxx part-specific data sheets have a memory map in section 4. Very useful to keep on hand as you work with the chip. Also as everything is accessed as a memory address, you'll come to know this layout like the back of your hand after a little programming time!
So after confirming that the flash has been properly configured we invoke the command to turn off write protection to the flash bank. PM0075 describes everything you need to know about programming the flash memory. What you need to know for this command is the flash bank, starting sector, ending sector, and whether to enable or disable write protection. The flash bank is defined in the configuration files you passed to OpenOCD and was confirmed by the previous command. Since I want to disable protection for the entire flash space I specify sectors 0 to 127. PM0075 explains how I got that number as it refers to how the flash memory is organized into 2KB pages for my (and your) device. My device has 256KB of flash so that means I have 128 pages. Your device has 512KB of flash so you'll have 256 pages. To confirm that your device's write-protection has been disabled properly, you can check the FLASH_WRPR register at address 0x40022020 using the OpenOCD command:
monitor mdw 0x40022020
The resulting word that it prints will be 0xffffffff which means all pages have their write protection disabled. 0x00000000 means all pages have write protection enabled.
Sidenote #3: On the subject of the memory commands, I bricked my chip twice as I was messing with the option bytes at the block starting at address 0x1ffff800. First time I set the read protection on the flash (kind of hard to figure out what your doing if you do that), second time I set the hardware watchdog which prevented me from doing anything afterwards since the watchdog kept firing off! Fixed it by using the OpenOCD memory access commands. Moral of the story is: With great power comes great responsibility.... Or another take is that if I shoot myself in the foot I can still fix things via JTAG.
Sidenote #4: One thing that'll happen if you try to write to protected flash memory is the FLASH_SR:WRPRTERR bit will be set. OpenOCD will report a more user-friendly error message.
Erasing the Flash
So after disabling the write protection, we need to erase the memory that you want to program. I do a mass erase which erases everything, you also have the option to erase by sector or address (I think). Either way you need to erase first before programming as the hardware checks for erasure first before allowing a write to occur. If the FLASH_SR:PGERR bit (0x4002200c) ever gets set during programming then you know you haven't erased that chunk of memory yet.
Sidenote #5: Erasing a bit in flash memory means setting it to 1.
Programming Your Binary
The next two lines after erasure writes the binary image to the flash and reenables the write protection. There isn't much more to say that isn't covered by PM0075. Basically any error that occurs when you issue flash write_image is probably related to the flash protection not being disabled. It's probably NOT OpenOCD though if you're curious you can take enable the debug output and follow what it does.
GDB Debugging
So finally after programming I disconnect GDB from the remote connection and then reconnect it to the target, do a soft-reset, and my GDB is now ready to debug. This last part I just figured out last night as I was trying to figure out why, after programming, GDB wouldn't properly stop at main() after reset. It kept going off into the weeds and blowing up.
My current thinking and from what I read in the OpenOCD and GDB manuals is that the remote connection is, first and foremost, meant to be used between GDB and a target that has already been configured and running. Well I'm using GDB to configure before I run so I think the symbol table or some other important info gets messed up during the programming. The OpenOCD manual says that the server automatically reports the memory and symbols when GDB connects but all that info probably becomes invalid when the chip gets programmed. Disconnecting and reconnecting I think refreshes the info GDB needs to debug properly. So that has led me to create another Debug Configuration, this one just connects and resets the target since I don't necessarily need to program the chip every time I want to use GDB.
Whew! Done! Kind of long but this took me 3 weekends to figure out so isn't too terribly bad I think...
Final sidenote: During my time debugging I found that OpenOCD debug output to be invaluable to me understanding what OpenOCD was doing under the covers. To program a STM32x chip you need to unlock the flash registers, flip the right bits, and can only write a half-word at a time. For a while I was questioning whether OpenOCD was doing this properly but after looking through the OpenOCD debug output and comparing it against what the PM0075 instructions were, I was able to confirm that it did indeed follow the proper steps to do each operation. I also found I was duplicating steps that OpenOCD was already doing so I was able to cut out instructions that weren't helping! So moral of the story: Debug output is your friend!
I struggled getting JLink to work with a STM3240XX and found a statement in the JLink GDB server documentation saying that after loading flash you must issue a "target reset":
"When debugging in flash the stack pointer and the PC are set automatically when the target is reset after the flash download. Without reset after download, the stack pointer and the PC need to be initialized correctly, typically in the .gdbinit file."
When I added a "target reset" in the Run box of the debugger Setup of Eclipse, suddenly everything worked. I did not have this problem with a Kinetis K60.
The document also explains how to manually set the stack pointer and pc directly if you don't want to issue a reset. It may not be the disconnect/connect that solves the problem but the reset.
What i use after the last sentence in the Comannd Tab - 'Run' Commands, is:
symbol-file STM3210CTest/test_rom.elf
thbreak main
continue
The thbreak main sentence is what makes gdb stop at main.
Related
I have an embedded board with an STM32 microcontroller, and an ST-Link v2. This setup generally works: I can program the flash, and connect with ST's CubeProgrammer tool or with openocd. I can attach gdb to the latter, and step through code. So far, so good. It does not appear there is any problem with my physical or electrical setup.
I have a program which is... not so good. Something early in initialization is hanging up the chip to the point where I can no longer connect to it with any tools. I can rescue it by using the "Under reset" mode of CubeProgrammer, holding the reset switch on the board at boot, then connecting before the bad program can wedge the chip.
After connecting this way, the chip is halted. I can flash a known good program. Or, I can use the MCU core screen of CubeProgrammer to "Step" one instruction at a time through the bad program's startup. That works, until I hit "Run", and then I quickly get a dialog "Warning: Connection to device 0x411 is lost", and the chip is no longer usable until I flash it as above. It appears the code is configuring the necessary pins into the alt mode to enable serial wire debugging, so I don't think that's the problem, but it's hard to verify.
So, it appears something in this program is behaving badly. What I'd like to do is set up gdb via openocd to debug startup. With a good program, I can connect with openocd while the program is running, attach gdb, and everything works normally. But I don't know how to get openocd to do what CubeProgrammer does with the "Under reset" mode, so I can execute initialization of the chip under gdb control.
How can I do this? Or, is there some other tool I should be trying than openocd+gdb? I'm familiar with gdb, but I can try other tools. The host environment is macOS.
Create an openOCD config file like this:
#
# stlink to stm32f2xx by swd with system reset and no test reset
#
source [find interface/stlink.cfg]
transport select hla_swd
source [find target/stm32f2x.cfg]
reset_config srst_only connect_assert_srst
And use the -f flag to openOCD to use it.
I have a hard drive was crypted by TryeCrypt,a custom edtion ,self input password,and i have found this 40-bytes password via MBR debugging, but can't mount it using standard version 7.1a.
what i want is get some files from this hard drive,good news is,this hard drive is bootable and it is a windows xp sp2,but a fullscreen app was auto startup and any input(keyboard,mouse etc.) was blocked,therefore,the only way to touch it is debugging it with vmware gdb stub.
The ida's remote dbg debugger is working very well, now I touch the guest's memory, edit it's codes, set breakpoints and the symbols was loaded.
so the question is,how can I start a process via patching the kernel?
What I thinking is,build a winddk project , implement a driver to do this with user APC, and then disassemble it to get it's assembler code ,and then patch it into guest via ida.
Any idea? thanks.
NonStop
Sets nonstop mode. If a terminal's already been set up, it's too late;
the debugger remembers the setting in case you restart, though. (source)
When is it useful,why do I need to debug if it doesn't ever stop?
As I understand it, you can use the debugger in rendez-vous-mode. In this setting, the debugger runs the application NonStop without a tty first, but when an event interrupt occurs, it stops the application and sets the tty up for you to debug.
Update: Rendez-vous-Mode is useful for attaching to a running perl process after it has been started (by something out of your control). If your application is prepared for dynamically loading the debugger, you can enter the debugger even if you did not start it with a -d option at all.
Just messing around with WinDbg a bit. I have a couple of virtual machines set up so I can try to do some kernel debugging on a Windows XP VM.
If I wanted to catch the system at its earliest possible moment during boot, where, or on what, would I need to set the breakpoint?
The earliest you can do is when KD connection is established and a first kernel module is loaded:
Break on first module load
The debugger breaks into a restarted target computer after the first kernel
module is loaded. (This action causes the break to occur earlier than in the
Break on reboot state.) This command is equivalent to starting WinDbg with
the -d command-line option.
To do that, you can either use the -d option on the command line as mentioned above, or you can press Ctrl+Alt+K in Windbg (or Ctrl+K if you use kd) to cycle through the initial breakin modes.
Adding /break at the end of your debugging entry in boot.ini should give you a breakpoint before module loading (right after HAL initialization.)
I'm working with Windows 7 64X and DebugView 4.76.0.0.
Logs isn't shown on DebugView.
I trying to write logs with Debug.WriteLine("Text"); and see nothing.
I can see that It's connected to my computer.
When I use DebugView V4.64.0.0 I get error message that it is already connected to other instance of DebugView, but I've checked and there isn't any other.
What can I do or check ?
BTW,
I can see the log in the output window.
Regards,
Eitan Gabay
To check if you really have another instance of debugview running, open up your task manager, and select "show processes from all users". Make sure that only one debugview is running.
When debugging through Visual Studio, Visual Studio actually competes against DebugView. If you were to compile your executable, and run it externally, you will see your log messages printed in DebugView.
One other thing that people sometimes overlook is that Debug.Write statements are excluded if a program is compiled for Release. However, you can still write to the trace if you use Trace.Write instead of Debug.Write.
All messages that you print go to a shared section of memory called DB_WINBUFFER link. It is important to realize that each windows session has its own "DB_WINBUFFER". Whenever DebugView detects that you are not in session 0, it will provide a "Capture Global" option. If your program is running as a windows service, then you will need to enable capture global (unless you are already in Session 0, which is only possible in Windows XP).