1. The first part contains the sections of an application that will remain, at runtime, in FLASH. The boot ROM does not need to parse these sections because they are already in the location where they need to reside at.
2. The second part contains the sections of an application that will reside, at runtime, in internal SRAM memory. Those are the sections that the boot ROM parses at boot time.
When developping an application to boot completely out of flash, each of the above two parts should be prepared into a loader file (.LDR):
Replace the following line in the LDF file (Note that as of VisualDSP++ 5.0 Update 8 of June 2010, the LDF already includes this change):
MEM_FLASH { TYPE(ASYNC0_MEMTYPE) START(0x20000000) END(0x203FFFFF) WIDTH(8) }
with the following two lines:
MEM_FLASH_BOOT { TYPE(ASYNC0_MEMTYPE) START(0x20000000) END(0x2001FFFF) WIDTH(8) }
MEM_FLASH { TYPE(ASYNC0_MEMTYPE) START(0x20020000) END(0x203FFFFF) WIDTH(8) }
This reserves a MEM_FLASH_BOOT memory region at the beginning of flash to be used for storing Loader file 2.
When building and loading an application that maps code and/or data into flash sections, as shown in the main source file of a LED blinking project below, the software tools will automatically generate Loader file 1 out of the routine "ClearSet_LED_inFlash" and will place in flash starting at address 0x2002_0000.
#define LED2 0x0001#define LED3 0x0002#define LED4 0x0004
#pragma section("L1_code")/******************************************************************** Function: ClearSet_LED* Description: Clear or set a particular LED (NOT A GROUP).*******************************************************************/void ClearSet_LED_inRAM(const int led, const int bState){ /* if bState is 0 we clear the LED, if bState is 1 we set the LED, else we toggle the LED */
if( 0 == bState ) { *pPORTFIO_CLEAR = led; } else if( 1 == bState ) { *pPORTFIO_SET = led; } else { *pPORTFIO_TOGGLE = led; }
}
#pragma section("FLASH_code")/******************************************************************** Function: ClearSet_LED* Description: Clear or set a particular LED (NOT A GROUP).*******************************************************************/void ClearSet_LED_inFlash(const int led, const int bState){ /* if bState is 0 we clear the LED, if bState is 1 we set the LED, else we toggle the LED */
int main( void ){ /* LED2 uses PF0, LED3 uses PF1, LED4 uses PF2 */
*pPORTF_FER &= (~(PF0 | PF1 | PF2)); /* Setup for LEDs */ *pPORTFIO_DIR |= (PF0 | PF1 | PF2); /* Setup port for output */ *pPORTFIO_CLEAR = (PF0 | PF1 | PF2); /* Turn all LEDs off */ while(1) { ClearSet_LED_inFlash( LED2, 0x1); ClearSet_LED_inFlash( LED3, 0x0); ClearSet_LED_inRAM( LED4, 0x1); } //return 0;
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The following steps show the procedure for generating Loader file 2:
Modify the VisualDSP project settings to generate a loader file of the RAM code sections.
a. Click Project –> Project Options… This will display the Project Options window
b. On the Project property page, select Loader file from the drop down menu next to Type.
c. On the Load:Options property page, ensure that the following options are selected:
i. Boot Mode is set to Flash/PROM
ii. Boot Format is set to Intel hex
iii. Output Width is set to 16-bit
d. On the Load:Splitter property page, ensure that Enable ROM splitter is not selected and click OK to save.
e. Click Project –> Build Project to build the project
f. Program the FLASH as follows:
i. In VisualDSP, select Tools –> Flash Programmer.
ii. In the Flash Programmer window, under the Driver tab, browse to the flash programmer driver, which is - at the time of this writing - located at: <VisualDSP installation directory>\Blackfin\Examples\ADSP-BF506F EZ-KIT Lite\Flash Programmer\BF50x4MBFlash\BF506FEzFlashDriver_BF50x4MBFlash.dxe
iii.Click on Load Driver
iv. Once the driver is loaded, select the Programming tab and browse to the LDR file that you just created in step e of these instructions.
v. Ensure that the appropriate selection is made under Pre-program erase options. The appropriate selection is usually Erase affected. refer to the IMPORTANT NOTE below for more information.
vi. Click on Program
Once both Loader files are generated and programmed in flash, (Loader file 1 is automatically generated and programmed by the software tools when the project is built and loaded, and Loader file 2 is manually generated and programmed as explained in the previous steps), the EZ-KIT's appropriate boot mode (boot from internal flash memory) may now be set and and EZ-KIT power may be cycled in order for the application to boot completely out of flash. When the power is cycled, the processor will boot, the loader file that was generated using the steps above (loader file 2) will be parsed by the on-chip boot ROM and will be loaded into internal memory and the execution will begin.
IMPORTANT NOTE: Since the flash is erased at a block granularity, it is important to ensure that when the two loader files are programmed into flash, they do not erase a block that the other loader file occupies. In the above example, we set the memory ranges in the LDF file appropriately such that the two loader files will not share any flash blocks. In practice, there are two ways to ensure that programming one of the two loader files does not erase the other: