In developing a stk500v2 XPROG bootloader for my product, I ran into a
problem with avrdude switching into the USB-only unframed version of the
protocol after SIGN_ON. It does so because of an assumption that every
stk500v2-xprog device will be communicating over USB. In my case I'm
running over a serial link (and soon running that over a mutliplexed
protocol), and the assumption is no longer correct.
I did a quick hack to the stk500v2.c code in order to make both cases
work. Basically it adds a struct var 'bareproto', which is used to
decide whether to send the stk500 commands framed or unframed, rather
than the specific programmer type. The flag itself is set when the
actual comms port is selected, and currently is only set if it's USB.
Being a quick hack I don't expect this patch to go anywhere itself.
However, something like it should be put in place, since non-USB XPROG
implementations are likely to show up (especially since I'll be
releasing mine at some point soon...).
Likely a better way to implement it would be an avrdude.conf flag that
would specifically set it to "framed-mode". Along those lines it would
be nice to have some way to define programmers by their SIGN_ON
responses. Since SIGN_ON is always sent in full stk500 framed mode no
matter what, having avrdude check through the .conf for a string match
(rather than hard-coded) and then picking up the "framed-mode" flag
before continuing would make it easy to define new programmer types for
bootloaders, etc.
Due to my development schedule I'm unable to do anything further on this
at this point, but if it's still an issue when I have a bit more time,
I'll see if I can give it a go.
Patch is attached, and I'll be filing it in the bug tracker in a couple
minutes.
Index: stk500v2.c
===================================================================
--- stk500v2.c (revision 947)
+++ stk500v2.c (working copy)
@@ -116,6 +116,7 @@
PGMTYPE_STK600,
}
pgmtype;
+ unsigned char bareproto;
AVRPART *lastpart;
@@ -455,8 +456,9 @@
unsigned char buf[275 + 6]; // max MESSAGE_BODY of 275 bytes, 6 bytes overhead
int i;
- if (PDATA(pgm)->pgmtype == PGMTYPE_AVRISP_MKII ||
- PDATA(pgm)->pgmtype == PGMTYPE_STK600)
+// if (PDATA(pgm)->pgmtype == PGMTYPE_AVRISP_MKII ||
+// PDATA(pgm)->pgmtype == PGMTYPE_STK600)
+ if (PDATA(pgm)->bareproto == 1)
return stk500v2_send_mk2(pgm, data, len);
else if (PDATA(pgm)->pgmtype == PGMTYPE_JTAGICE_MKII)
return stk500v2_jtagmkII_send(pgm, data, len);
@@ -558,8 +560,9 @@
struct timeval tv;
double tstart, tnow;
- if (PDATA(pgm)->pgmtype == PGMTYPE_AVRISP_MKII ||
- PDATA(pgm)->pgmtype == PGMTYPE_STK600)
+// if (PDATA(pgm)->pgmtype == PGMTYPE_AVRISP_MKII ||
+// PDATA(pgm)->pgmtype == PGMTYPE_STK600)
+ if (PDATA(pgm)->bareproto == 1)
return stk500v2_recv_mk2(pgm, msg, maxsize);
else if (PDATA(pgm)->pgmtype == PGMTYPE_JTAGICE_MKII)
return stk500v2_jtagmkII_recv(pgm, msg, maxsize);
@@ -1283,6 +1286,7 @@
baud = pgm->baudrate;
PDATA(pgm)->pgmtype = PGMTYPE_UNKNOWN;
+ PDATA(pgm)->bareproto = 0;
if(strcasecmp(port, "avrdoper") == 0){
#if defined(HAVE_LIBUSB) || (defined(WIN32NATIVE) && defined(HAVE_LIBHID))
@@ -1304,7 +1308,9 @@
#if defined(HAVE_LIBUSB)
serdev = &usb_serdev_frame;
baud = USB_DEVICE_AVRISPMKII;
- PDATA(pgm)->pgmtype = PGMTYPE_AVRISP_MKII;
+// PDATA(pgm)->pgmtype = PGMTYPE_AVRISP_MKII;
+ fprintf(stderr,"setting bare protocol\n");
+ PDATA(pgm)->bareproto = 1;
pgm->set_sck_period = stk500v2_set_sck_period_mk2;
#else
fprintf(stderr, "avrdude was compiled without usb support.\n");
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