Re: [Qemu-devel] [PATCH v1 0/1] Fix GDB semihosting

[Peter Maydell]

On 15 February 2012 16:55, Meador Inge <address@hidden> wrote:
> This patch fixes the problem be staying in the 'RS_SYSCALL' state until next
> packet read comes in.  Therefore keeping any 'T' statuses from being sent
> back to the GDB client while the syscall is still being processed.

Wouldn't it be more logical to stay in "we are processing a syscall"
state until we actually get the whole reply packet and process it
rather than merely until we get the first byte of the reply?
(this probably implies it being a separate flag rather than an RSState
state, but that's cleaner anyhow I think since the RSStates represent
the state machine as we work through parsing the packet, and RS_SYSCALL
isn't a distinct parsing state.)

This patch works (in that it fixes this problem with a test case I have
coincidentally received from another reporter this week), although I
notice that doing read/write syscalls via gdb is dreadfully slow
because there seems to be ~1second delay between gdb sending its response
to a syscall (Fwrite/Fread) packet and getting the ack back from qemu.
I'm guessing that's a different bug...

-- PMM