TM4C1292NCPDT: 07/10/2017

sandra george78

Part Number: TM4C1292NCPDT

Hii,

I am doing a boot code from which two firmware images have to be executed. The boot code and the two firmware images have to be stored in flash memory. They are stored as shown in the memorymap snippet.

A variable have to be stored in the flash memory in the common memory region as in the snippet and according to the variable a switching have to be done between firmware images. How can I store, update and read a variable in flash memory ? Also, I have to execute the firmware image from flash memory. I tried using the function (*((void (*)(void))(*(uint32_t *)0x00004000)))(); . Is it enough to execute from flash address?

I loaded the program to the evaluation board connected with a USB cable using LM flash programmer utility. When I loaded blinky.bin to 0x00000000 it worked. But when I loaded to 0x00004000 it did not work. What may be the reason? If I load a bin file initially to an address and if I again load a program to 0x00000000 will the program be retained in the address?

I loaded blinky.bin to 0x00004000 and then boot code to 0x00000000. I have to execute the blinky.bin from the boot code. I have done as shown in the snippet.

Am I in the right way? Please give me necessary advise.

Thanks & Regards

Sandra

over 8 years ago

0 Bob Crosby over 8 years ago

TI__Guru 72500 points

Hi Sandra,
The typical application starts with the CPU loading the stack pointer from address 0x0 and the PC from address 0x4. In your case, the typical application will be the boot loader. To transfer control to another application in firmware, you emulate the loading of the stack pointer and PC with the assembly code like you have above. You also must link the application to start and run at the different location. This you can do by modifying the link command file "<project_name>_ccs.cmd.

0 sandra george78 over 8 years ago in reply to Bob Crosby

Intellectual 980 points

Hi Bob,

I did the code as shown below. Is this how you meant?

Also, I edited in cmd file as,

But the firmware image from 0x4000 is not executed. What should I do more? Please tell me a suggestion.

Thanks & Regards

Sandra

0 Bob Crosby over 8 years ago in reply to sandra george78

TI__Guru 72500 points

SRAM should not change. It is still at 0x20000000.

0 sandra george78 over 8 years ago in reply to Bob Crosby

Intellectual 980 points

Bob,

Now I changed the SRAM address.

Again, the result is same. What can I do further? Please guide me.

Thanks & Regards

Sandra

0 Bob Crosby over 8 years ago in reply to sandra george78

TI__Guru 72500 points

Did the application run correctly without the bootloader and APP_BASE set to 0x00000000? If it did, then you will need to debug the bootloader to see that it is properly calling the assembly language instructions and transferring execution to the application.

0 sandra george78 over 8 years ago in reply to Bob Crosby

Intellectual 980 points

Hi Bob,

Thank you very much for your guidance. Now the image is running from boot code.

Thanks & Regards

Sandra

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TM4C1292NCPDT: 07/10/2017