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Diffstat (limited to 'doc/openocd.texi')
| -rw-r--r-- | doc/openocd.texi | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/doc/openocd.texi b/doc/openocd.texi index ef395ea2..a83c966b 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -6497,6 +6497,21 @@ a bit of googling to find something that fits your requirements. @cindex GDB OpenOCD complies with the remote gdbserver protocol, and as such can be used to debug remote targets. +Setting up GDB to work with OpenOCD can involve several components: + +@itemize +@item OpenOCD itself may need to be configured. @xref{GDB Configuration}. +@item GDB itself may need configuration, as shown in this chapter. +@item If you have a GUI environment like Eclipse, +that also will probably need to be configured. +@end itemize + +Of course, the version of GDB you use will need to be one which has +been built to know about the target CPU you're using. It's probably +part of the tool chain you're using. For example, if you are doing +cross-development for ARM on an x86 PC, instead of using the native +x86 @command{gdb} command you might use @command{arm-none-eabi-gdb} +if that's the tool chain used to compile your code. @anchor{Connecting to GDB} @section Connecting to GDB @@ -6528,19 +6543,34 @@ session. To list the available OpenOCD commands type @command{monitor help} on the GDB command line. +@section Configuring GDB for OpenOCD + OpenOCD supports the gdb @option{qSupported} packet, this enables information to be sent by the GDB remote server (i.e. OpenOCD) to GDB. Typical information includes packet size and the device's memory map. +You do not need to configure the packet size by hand, +and the relevant parts of the memory map should be automatically +set up when you declare (NOR) flash banks. + +However, there are other things which GDB can't currently query. +You may need to set those up by hand. +As OpenOCD starts up, you will often see a line reporting +something like: -Previous versions of OpenOCD required the following GDB options to increase -the packet size and speed up GDB communication: @example -set remote memory-write-packet-size 1024 -set remote memory-write-packet-size fixed -set remote memory-read-packet-size 1024 -set remote memory-read-packet-size fixed +Info : lm3s.cpu: hardware has 6 breakpoints, 4 watchpoints @end example -This is now handled in the @option{qSupported} PacketSize and should not be required. + +You can pass that information to GDB with these commands: + +@example +set remote hardware-breakpoint-limit 6 +set remote hardware-watchpoint-limit 4 +@end example + +With that particular hardware (Cortex-M3) the hardware breakpoints +only work for code running from flash memory. Most other ARM systems +do not have such restrictions. @section Programming using GDB @cindex Programming using GDB |