On 18/8/2023 7:01 am, Kinsey Moore wrote: > On Thu, Aug 17, 2023 at 7:11 AM Kinsey Moore <kinsey.mo...@oarcorp.com > <mailto:kinsey.mo...@oarcorp.com>> wrote: > > On Wed, Aug 16, 2023 at 9:42 PM Chris Johns <chr...@rtems.org > <mailto:chr...@rtems.org>> wrote: > > On 17/8/2023 6:30 am, Kinsey Moore wrote: > > The current ARM support in libdebugger does not cover Cortex-M > series > > cores since it requires support for CP14 system register accessor > > instructions. Cortex-M series cores support debug monitor mode, but > its > > configuration is accessed by memory mapped registers instead of > using > > CP14. This omits building libdebugger from BSPs that use a cortex-m > ABI > > flag. > > The ARM libdebugger has support to use memory mapped registers. It is > determined > by the ROM and then rtems_debugger_arm_debug_registers. I think the > code > currently assume CP14 instructions but I think that could be made > conditional > where needed? > > Are these builds of Cortex-M processors able to support libdebugger? > > I have been rejecting changes like this unless there is a reason it > cannot be > made to work. Are there reasons it cannot be made to work? > > > As to my current understanding, I believe that the Cortex-M3/4/7 cores can > support libdebugger via their exclusive monitor mode. I'll see if I can > work > around the CP14 issues instead. > > > Reading into the relevant Architecture and Technical reference manuals, the > ROM > tables in the Cortex-M cores do not expose information about the debug and > data > watchpoint blocks. It looks like all the breakpoint (0xE0002000) and > watchpoint > (0xE0001000) controls are the same IP at the same address across the Cortex-M > line, but are in no way compatible with the CP14-based breakpoint and > watchpoint > blocks in the Cortex-A/R lines of cores. The Cortex-M cores require a nearly > unrelated libdebugger implementation.
Thanks for this and looking into it. I am fine with the change now we understand it is not compatible. It sounds like a new back end would be cleaner for both types of devices. The patch is approved. Chris _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel