[avrdude-dev] patches #5008. 5025 and 5293 needed in our configuration for stk500 support

[Matthias Ringwald]

Hi there

we're using avrdude to program our BTnodes (btnode.ethz.ch).

Although the linux version works properly, the current cvs version does 
not allow to use avrdude on mac os x and cygwin environments.
We're using a stk500 emulating bootloader (/btnut/apps/bootloader) and
normal AVR ISP programming devices.

In our set-up the BTnode is connected via a Silabs cp2102 usb to serial 
bridge. On mac os x, the non-blocking default behaviour prevents this
adapter to work at all (the app just hangs and crashes the usb driver).
This issues is solved by patch #5008

But then, avrdude is sending the page_write command in three steps
and because of the non-blocking, this gets screwed up. Replacing the
three writes with a single write solves this issue. patch #5025

On cygwin, we encountered a problem with avrdude and our bootloader.
We first start avrdude and then press the RESET button on the device.
The bootloader send 0x14 0x10 back over the serial line and expects
the host pc to respond immediately (200 ms). If command is received,
we start the main app.
In the current stk500.c, drain() is called after waiting for the sync
(without a reason) causing the bootloader to give up. We just submitted
patch #5293 which just removes the drain call.

could those patches be applied to the current cvs (and hopefully be
included in the next avrdude + winavr releases?).

I'm using avrdude with patches 5008 and 5025 since I got it working and
didn't experience any problems.

Thanks,
 Matthias Ringwald
 ETH Zurich