TMS570LC4357: bootloader with rtos

qing yu

Part Number: TMS570LC4357

Tool/software:

HI :

I found the way of bootloader exception handling on the following webpage. It is as follows:

1 Issue with bootloading and RTOS - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Application start address is: 0x00010020

Here is HL_sys_intvecs.asm from bootloader

; interrupt vectors

b _c_int00 ;0x00
b #0x10018 ;
b #0x10018 ;
b #0x10018 ;
b #0x10018 ;
b #0x10018 ;0x14
ldr pc,[pc, #-0x1b0] ;0x18
ldr pc,[pc, #-0x1b0] ;0x1C

2 TMS570LC4357: Boot-loader with uC/OS-III Application - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

; interrupt vectors


        b   _c_int00
        b   #0x2000F8
        b   #0x2000F8
        b   #0x2000F8
        b   #0x2000F8
        b   #0x2000F8
        b   #0x2000F8
        b   #0x2000F8

Why is the interrupt vector in the bootloader set to jump to a location that is 8 bytes before the application start address? Shouldn't it jump to the address obtained by adding the application start address and the interrupt vector multiplied by 4?

For example, Why not like the following?

        b   _c_int00
        b   #0x200104
        b   #0x200108
        b   #0x20010C
        b   #0x200110
        b   #0x200114
        b   #0x200118
        b   #0x20011C

Thanks

over 1 year ago

0 jagadish gundavarapu over 1 year ago

TI__Guru 73741 points

Hi Qing Yu,

qing yu said:
Why is the interrupt vector in the bootloader set to jump to a location that is 8 bytes before the application start address? Shouldn't it jump to the address obtained by adding the application start address and the interrupt vector multiplied by 4?

For example, Why not like the following?

You are correct.

And your branch statements are correct if we store the application vector table at 0x200100

qing yu said:
b _c_int00 b #0x200104 b #0x200108 b #0x20010C b #0x200110 b #0x200114 b #0x200118 b #0x20011C

And i think he also did the same mistake first time, that is why if you refer his last comment in the below thread:

(+) TMS570LC4357: Boot-loader with uC/OS-III Application - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

That means he didn't link the bootloader and application branches properly for the first time, that created issue for him.

However, you are correct with below branches if we store our application vector table at 0x200100.

qing yu said:
b _c_int00 b #0x200104 b #0x200108 b #0x20010C b #0x200110 b #0x200114 b #0x200118 b #0x20011C

--
Thanks & regards,
Jagadish.