Need help in writing a bootloader on EK-TM4C123GXL Evaluation Board

Hi,

TM4C123xx micros have all an embedded bootloader, in on-chip ROM area. Also, the source code for bootloader is in Tiva/bootloader, so you may read/modify if needed. Documentation in Tiva/docs.

Petrei

Hey,

Thank You but my project is to write a custom bootloader. Basically I have to port the bootloader that i have for 33f dspic to arm m4 processor. I have not worked on the arm before thus I am having trouble porting the bootloader. 

Reshma

Hi,

OK then, looking to the specific Cortex-M4 in the bootloader source code and paste your from dspic33. Take into account the differences in hardware from one micro to another. Some specific requests?

Petrei

These are my requirements but I am still not clear about how to start off

The bootloader solution should support fixed 1k page(s) at address 0x0 for the bootloader code. These
first pages should not be modified or erased during the bootloading process.
UART0 should be used to program the device at a rate of 115200 8N1.
To support interrupt in the loaded application without changing the first page code containing the intvec,
the VTOR should be changed for normal application operation.
No calls to ROM functions are allowed, as the purpose is to illustrate functionality in future semesters, not
just call the ROM or flash bootloader API. 

Hello Reshma,

Petrei's point is very simple. There are differents between the dspic and cortex-M4 (tiva in this case) that you need to take into account. It is not an industry wide standard on peripherals like UART on how the system view should be for different architectures. The same applies on the Sector sixe of Flash. It may or may not meet all the requirements you may have porting the same from your existing device framework to Tiva.

I would ask you to look at

C:\ti\TivaWare_C_Series-2.1.0.12573\examples\boards\dk-tm4c123g\boot_serial

which has the UART based boot loader for TM4C123 devices.

Regards

Amit

Thank You I will take a look at that and start off with my project. If i get stuck at some point I will get back to you

Thank You

Hello Reshma

Please note that while you are free to select a tool chain with TM4C devices, we ma be able to support you better with a limited number of full version IDE's.

Regards

Amit

Hello Amit,

in order to reconstruct 0xABCDED12 in the FMD, can i perform left shift on the FMD register to shift AB from lsb to the msb and write the other received bytes into the FMD register.

Thanks

Hello Reshma,

The FMD register during a read is undetermined. It would be advisable to do the same using a variable and then writing the final value to the FMD register.

Regards

Amit

there is a Commit register in flash memory control register, there is the WRKEY which needs to be polled until the write to the flash is complete, do we need to check the COMT register as well.

thanks

I am not able to write the eraze bit in FMC  register. 

Hello Reshma,

When programming the word the WRITE bit needs to be set. Also when you write the operation does not take much time. So if we use the debugger-step to check the FMC bit it will get cleare. You can check if the Address in flash has the data programmed

Regards

Amit

I tried to load SP and PC as shown in the forumn but it is still not pointing to the right address.

 __asm(" ldr r1, [r0]\n"
        " mov sp, r1");

        __asm(" ldr r0, [r0, #4]\n"
        " bx r0\n");

thats what I used 

Hello Reshma

Seems like you have two threads running. we will move it to the new thread...

Regards

Amit