Application Management

General Description

DFU Functions for application management.

Functions
void	Cy_DFU_ExecuteApp (uint32_t appId)
	This function transfers control from the current application to another application. More...
void	Cy_DFU_OnResetApp0 (void)
	This function is used in an App0 firmware image in Reset_Handler() only. More...
uint32_t	Cy_DFU_GetRunningApp (void)
	This function reports the application number of the currently running application. More...
cy_en_dfu_status_t	Cy_DFU_SwitchToApp (uint32_t appId)
	This function switches to the application through the jump instruction. More...
cy_en_dfu_status_t	Cy_DFU_CopyApp (uint32_t destAddress, uint32_t srcAddress, uint32_t length, uint32_t rowSize, cy_stc_dfu_params_t *params)
	This function copies an application from a temporary location in flash to its destination location in flash. More...
cy_en_dfu_status_t	Cy_DFU_ValidateApp (uint32_t appId, cy_stc_dfu_params_t *params)
	This function reports whether or not metadata and the specified application is valid. More...

Function Documentation

Cy_DFU_ExecuteApp()

void Cy_DFU_ExecuteApp

(

uint32_t

appId

)

This function transfers control from the current application to another application.

The function performs switching via software reset. In case if application need to switch without reset, for example if it needs to enable some peripheral during and after the application switching, use Cy_DFU_SwitchToApp(). The function does not return.

Note

It is assumed appId is a valid application number.

Parameters

appId

An application number of the application to switch to.

Cy_DFU_OnResetApp0()

void Cy_DFU_OnResetApp0

(

void

)

This function is used in an App0 firmware image in Reset_Handler() only.

Checks if switching to the other application is scheduled with Cy_DFU_ExecuteApp().
If the switch is scheduled, then it validates the application and transfers control to it.

Cy_DFU_GetRunningApp()

uint32_t Cy_DFU_GetRunningApp

(

void

)

This function reports the application number of the currently running application.

Returns

application number

Cy_DFU_SwitchToApp()

cy_en_dfu_status_t Cy_DFU_SwitchToApp

(

uint32_t

appId

)

This function switches to the application through the jump instruction.

The function should be used when an application switching must be done without a software reset. Possible reason is a need to enable some peripheral during and after the application switching. In other case use Cy_DFU_ExecuteApp().

Before calling this function, ensure all the peripherals and bus masters are in a known state. User is responsible to disable peripherals and to set MCU internal state before or after an application switching.

Note

It is assumed appId is a valid application number.

Parameters

appId

An application number of the application to switch to.

Returns

It doesn't return if succeeds. If failed, returns the status code. See cy_en_dfu_status_t.

Cy_DFU_CopyApp()

cy_en_dfu_status_t Cy_DFU_CopyApp	(	uint32_t	destAddress,
		uint32_t	srcAddress,
		uint32_t	length,
		uint32_t	rowSize,
		cy_stc_dfu_params_t *	params
	)

This function copies an application from a temporary location in flash to its destination location in flash.

This function is typically called when updating an application used as part of an update process, for example updating a BLE stack.

Note

This API is only for demonstration purpose, use it only when copying from internal flash to internal flash. For other user cases, implement a custom, more general function.

Parameters

destAddress	The start address of the application to copy to.
srcAddress	The start address of the copy of the application to be copied.
length	The number of bytes to copy.
rowSize	The size of a flash row in bytes.
params	The pointer to a DFU parameters structure. See cy_stc_dfu_params_t .

Returns

See cy_en_dfu_status_t.

Cy_DFU_ValidateApp()

cy_en_dfu_status_t Cy_DFU_ValidateApp	(	uint32_t	appId,
		cy_stc_dfu_params_t *	params
	)

This function reports whether or not metadata and the specified application is valid.

It checks:

• checksum for applications without format;
• application signature for Cypress Standard User Application format.

This is a weak function and the user may override it in the user's code by providing a function with the same name.

Note

It is assumed appId is a valid application number.

Parameters

appId	The application number of the application to be validated.
params	The pointer to a DFU parameters structure. See cy_stc_dfu_params_t .

Returns

See cy_en_dfu_status_t.

• CY_DFU_SUCCESS If the application is valid.
• CY_DFU_ERROR_VERIFY If the application is invalid.