TMS570LS3137: About Reset Handler and Vector Table for Booting Process.

Berat Yildizer

Part Number: TMS570LS3137

Tool/software:

Hello everyone,

I have some miss points about developing custom bootloader for TMS570LS3137 MCU. When I look at the relevant documents I saw that reset handler is started from 0x00000000. Also, I saw that vector table adress is located in the system module (address is 0xFFF82000).

I will have two different software, one of them is my bootloader software another is my application.I will load them to different flash regions by editting linker file (I will reside bootloader software in starting from 0x0000000 adress). As far as I see, vector table adress will be same for both software even though both software are located in the different regions on flash. Is it correct?

Also, I have one more question about reset handler. As I said above, _c_int00(reset handler) is stored in the beginning of flash memory(0x00000000). However, I will have application software and its region to be loaded wil be different. For this situation, where will be located reset handler or _c_int00 function for app software?

Thank you for your responses in advance!

over 1 year ago

+1 jagadish gundavarapu over 1 year ago

TI__Guru 73401 points

Hi Berat,

Berat Yildizer said:
As far as I see, vector table adress will be same for both software even though both software are located in the different regions on flash. Is it correct?

Here two vector tables will be there:

1. Exception Vector Table:

This exception vector table consists of resetEntry, prefetchEntry, undefEntry and dataEntry etc. After reset entry the CPU comes to this exception table and reads the address stored in resetEntry and that is _c_int00 and go through that function and starts exectution.

Similarly, if any exception occurs during execution, then CPU will read the corresponding exception address and do the process.

And this table can be different for both bootloader and application.

Refer below two threads to understand how to use it:

(7) RM48L952: When implementing the BootLoader function, how to realize the redirection of the exception vector table before jumping to the APP? - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(7) TMS570LC4357: Move the start address of the program - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

The bootloader exception vector table should always be at 0x00000000 address and application exception table should just be before the application code starts.

As we discussed after reset the processor will execute the bootloader exception table resetEntry right, and now after bootloader performs its operation and this bootloader now will call the reset entry of the application exception table.

2. Interrupt Vector table:

This table will consist of addresses for interrupts, and it is always located at the address 0xFFF82000.

And this table relocation is not possible:

(+) TMS570LS3137: How do I remap abort interrupt vectors - Processors forum - Processors - TI E2E support forums

And this table will be common for both bootloader and application.

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Thanks & regards,
Jagadish.