Instead of checking for the NEW_LUFA_SIGNATURE once in program memory and then
setting a flag which is used for further checks, a function is used that always
checks program memory directly.
If a flag is used, there's a slight chance that its location in RAM could fall
on MAGIC_KEY_POS. In this case, an aborted USB auto-reset sequence may fail.
An auto-reset invoked using USB CDC is triggered by the port closing
(when set to 1200 baud). Closing of the port is indicated by DTR going inactive.
There is no need to have auto-reset invoked by a CDC_SET_LINE_CODING command.
Only the CDC_SET_CONTROL_LINE_STATE command, which indicates a change in the
state of DTR, should be used.
In the USB CDC code to invoke an auto-reset, the magic key location could be
restored before it had actually been saved. The sketch would then have a
corrupted value at this location. This fix prevents the value from being
restored if it hasn't previously been saved.
Replaces #4280, only checks for the bootloader once
Tested with Hoodloader2, should work with every LUFA-derived bootloader released after 2014 (.apitable_signatures section must be placed at end of the flash)
BootloaderAPITable.S :
.global BootloaderAPI_Signatures
BootloaderAPI_Signatures:
.long BOOT_START_ADDR ; Start address of the bootloader
.word 0xDF00 ; Signature for the CDC class bootloader
.word 0xDCFB ; Signature for a LUFA class bootloader
makefile:
BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures, BootloaderAPI_Signatures, 8)
This makes the CDC "Serial" object on the Leonardo and similar boards
support this recently introduced method as well. The CDC code in the sam
core is not changed.
This allows detecting when the USB host sends a break request and what
the value of the request was. See the comments in USBAPI.h for details.
This just modifies the avr core, not the sam core.
This allows a sketch to find out the settings chosen by the USB host
(computer) and act accordingly.
Other than reading the DTR flag and checking if the baudrate is 1200,
the regular CDC code doesn't actually use any of these settings.
By exposing these settings to the sketch, it can for example copy them
to the hardware UART, turning the Leonardo into a proper USB-to-serial
device. This can be useful to let the computer directly talk to whatever
device is connected to the hardware serial port (like an XBee module).
The Teensy core already supported these methods. This code was
independently developed, but the method names were chosen to match the
Teensy code, for compatibility (except that `dtr()` and `rtr()` return
`bool`, while the Teensy version return a `uint8_t`).
This change is applied to both the avr and sam cores, which have a very
similar CDC implementation.
and restore it in case of aborted reboot
use RAMEND-1 as suggested by @yyyc514 in PR #2474
of course it's not a real solution but we cannot force everyone to update the bootloader using an external programmer
Mostly useful for Leonardo - simple way to test whether the port is actually opened by an application and ready to receive data. For Serial objects attached to real UARTs always returns true.
Since we use a magic RAM flag to signal to the bootloader there's a risk of the sketch overwriting the magic RAM location before the bootloader starts. By reducing the watchdog timeout we reduce the chance of this happening.
Before the sketch initiates an auto-reset for upload it pokes a magic word into a specific RAM address. On starting the bootloader checks this address. If it finds the magic word it knows the bootloader code should run. If not it jumps straight back to sketch.
Test in a sketch by adding to setup():
wdt_enable(WDTO_2S);
Sketch should upload, start, run for two seconds, WDT, and sketch should restart (not bootloader).
Had to cut out unused descriptor code to make the bootloader still fit in 4k.
On Windows COM port changes when board switched between bootloader and sketch. No way to prevent this so now Windows users have to select the upload port separate from the comm port. Also, handling of reset into bootloader was broken on Windows. Would occasionally leave the original COM port completely unusable. Changed the way this reset is initiated.
Finally, had to add upload.disable.flushing=true flag to boards.txt so IDE wouldn't try to flush the original COM port after it disappeared.
This fixes the issue Federico reported where bytes written by host but not read by sketch would cause serial connection to lock up. Ring buffer implementation is based on HardwareSerial.cpp.
Adds public accept() method to CDC.
Scott Allen
Martino Facchin
Nico
Cristian Maglie
Peter Van Hoyweghen
Matthijs Kooijman
Cristian Maglie
Paul Brook
Justin Rajewski
Peter Van Hoyweghen
Zach Eveland
Federico Vanzati