DFU: Introduce board/app-specific override for booting in DFU mode

Using the USBDFU_OverrideEnterDFU() function, a board/application can
define extra conditions when the system should boot in DFU mode, even if
it was not explicitly switched to DFU mode from the application.

The app/dfu/main.c uses this mechanism to boot into DFU mode if the
stack + reset vector addresses are not plausible (i.e. some random junk
appears to be flashed in the application partition) or if the user
places a jumper accross the RxD+TxD lines of the debug UART.  The idea
is that the system can be recovered by placing this jumper and then
re-installing the application from DFU.
This commit is contained in:
Harald Welte
2017-03-04 19:17:27 +01:00
parent 7214b4747f
commit 1405100dff
4 changed files with 61 additions and 1 deletions

View File

@@ -110,6 +110,7 @@ extern int USBDFU_handle_dnload(uint8_t altif, unsigned int offset,
uint8_t *data, unsigned int len);
extern int USBDFU_handle_upload(uint8_t altif, unsigned int offset,
uint8_t *data, unsigned int req_len);
extern int USBDFU_OverrideEnterDFU(void);
/* function to be called at end of EP0 handler during runtime */
void USBDFU_Runtime_RequestHandler(const USBGenericRequest *request);

View File

@@ -472,6 +472,14 @@ void USBDFU_SwitchToApp(void)
NVIC_SystemReset();
}
/* A board can provide a function overriding this, enabling a
* board-specific 'boot into DFU' override, like a specific GPIO that
* needs to be pulled a certain way. */
WEAK int USBDFU_OverrideEnterDFU(void)
{
return 0;
}
void USBDCallbacks_RequestReceived(const USBGenericRequest *request)
{
USBDFU_DFU_RequestHandler(request);