GDB support for flash: implementation

[Jim Blandy]

Daniel Jacobowitz <drow@false.org> writes:
> On Mon, Jun 05, 2006 at 11:34:12AM -0700, Jim Blandy wrote:
>> The GDB load command initially tries to place the program image in
>> memory using ordinary memory write requests --- remote protocol M or X
>> requests. However, when the stub detects that GDB has attempted to
>> write to flash memory, it returns an error code of the form:
>> 
>>         Eflash:addr;length
>> 
>> In this reply, addr and length are the start address and length of the
>> block of flash memory the write request attempted to modify. That is,
>> a write that overlaps any portion of a region of flash memory elicits
>> an Eflash response giving the location and size of the entire flash
>> memory. If the write request overlaps two areas of flash, the Eflash
>> request reports the lowest-addressed area. When the stub returns an
>> Eflash result, it should discard the entire write request; if portions
>> of the request cover non-flash memory, the contents of that memory
>> should be unchanged.
>
> Jim and I were talking about this earlier and didn't really come to a
> conclusion.  I don't like Eflash; I think it's unnecessarily
> complicated, and that it would actually be simpler to ask the target
> to tell us where its flash is.

To be clear: once GDB knows where the flash is, you think the rest of
the proposal is okay, right?