F28M35H52C: F28M35 M3 Bootloader: how to jump to application code ?

Ril

I apologize for the delay. Have you had any success branching to the entry point?

When branching to address, the BLX instruction will result in usagefault if bit[0] is 0.
To branch to an address, I've used the following:

entry_addr = 0x1234; //This is the address of the function I want to branch to
entry_addr |= 0x1; //This satisfies the condition I just mentioned
((void (*)(void))entry_addr)(); //This calls the function at that address

Best regards
Chris

Hi Chris, thanks for your answer.

I still didn't have any success with this.

When you talk about entry_addr, you mean the main function address of the application right ? Can it be this simple ? When are the global and static variables initialized?

When I do that without anythig else, I get the following error in the debugger:

"""

ti.sysbios.family.arm.m3.Hwi: line 1087: E_hardFault: FORCED
ti.sysbios.family.arm.m3.Hwi: line 1199: E_usageFault: INVSTATE: Invalid EPSR and instruction combination
Exception occurred in background thread at PC = 0x00000000.
Core 0: Exception occurred in ThreadType_Task.
Task name: {unknown-instance-name}, handle: 0x20000238.
Task stack base: 0x20000288.
Task stack size: 0x800.
R0 = 0x00000000  R8  = 0xffffffff
R1 = 0x00000000  R9  = 0xffffffff
R2 = 0x00000075  R10 = 0xffffffff
R3 = 0x00000001  R11 = 0xffffffff
R4 = 0x00000001  R12 = 0x00000000
R5 = 0x00000075  SP(R13) = 0x200009b0
R6 = 0x00000000  LR(R14) = 0x00224cc3
R7 = 0xffffffff  PC(R15) = 0x00000000
PSR = 0x00000000
ICSR = 0x0440f803
MMFSR = 0x00
BFSR = 0x00
UFSR = 0x0002
HFSR = 0x40000000
DFSR = 0x00000001
MMAR = 0xe000ed34
BFAR = 0xe000ed38
AFSR = 0x00000000
Terminating execution...

"""

When I add before that:

HWREG(NVIC_VTABLE) = APP_FLASH_START; // Tried values 0x00220000, 0x00220004, 0x00220005...

I get no apparent error, but the debugger shows me line 117 of /.../ti/ccsv6/tools/compiler/arm_15.12.3.LTS/lib/src/trgmsg.c :

    for (i = 0; i < length; i++) PACKCHAR(*data++, p, i+8);

and nothing else happens.

Could you provide a more complete example of what you did? Apparently, it worked for you.

I would appriciate if you could also tell me how you programmed your firmware(s) to flash.

Thanks again for your support.

Ril

Ril

You should branch to _c_int00 (see controlSUITE examples' statup_ccs.c), this procedure part of the RTS library, does all that pre-variable setup and then at the end branches to the "main" symbol.

I've used this method of branching as part of the boot code, not for firmware update. Refer to controlSUITE examples for programming flash. I will see if I can find any firmware update code, not sure if we have some.

Best regards
Chris

Christopher,

Did you have any chance to find this example somewhere ?

We tried the following without success :

// equivalent to FLASH_BOOT in b.cmd (see below)
// we also tried with 0x220004, equivalent to FLASH in b.cmd
#define APP_START 0x220000  

void JumpToFlashB()
{
   uint32_t entry_addr = 0x23A9ED; // This is the address of the function _c_int00 in the other application
   entry_addr |= 0x1;
   HWREG(NVIC_VTABLE) = APP_START; // With or without this line
   ((void (*)(void))entry_addr)();
}

I was wondering if the way I link the stages was leading to something wrong.

Here is what I have in my cmd file (simplified):

A.cmd

MEMORY
{
   FLASH_BOOT (RWX)    : origin = 0x00200030, length = 0x00000004
   FLASH (RWX)         : origin = 0x00200034, length = 0x0001FFCC
   RSVD_B (RWX) : origin = 0x00220000, length = 0x0005FF00 // Jump to this sector with JumpToFlashB()
}

B.cmd

MEMORY
{
   RSVD_A (R) : origin = 0x00200030, length = 0x0001FFD0
   FLASH_BOOT (RWX)    : origin = 0x00220000, length = 0x00000004
   FLASH (RWX)         : origin = 0x00220004, length = 0x0005FEF8 // Starts at sector xxx
}

Any idea or functional example on your side ?

Cheers,

Ril

Sorry, I haven't had any luck finding an example. It is looking like we don't have one currently.
The address you're calling has (or have tried) a function that calls c_int00.
Ex from "startup_ccs.c" in controlSUITE:
void myfunc()
{
// Jump to the CCS C Initialization Routine.
__asm(" .global _c_int00\n"
" b.w _c_int00");
}

You're getting the same error as you mentioned previously?

Best regards
Chris

Hello Chris,

Christopher Chiarella said:

You're getting the same error as you mentioned previously?

Yes, I have the same behavior when doing the call like that.

After looking at this post: https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/660862   , I can reproduce the same behavior : I set a break point at the call, then do 'Step into' and the application code starts (with a few driver issues). Any idea how this is happening ?

I feel like there is something more to do, like settings interrupt vectors ? 

On a side note, I can reboot 'on myself' without issue by calling _c_int00, but it fails when calling the same function from the second stage.

Thanks for your help Chris.

Ril

Ril,

I posted few debug steps on the forum post  https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/660862, you pointed to.

I don;t think there is anything wrong with the branch itself, it could be failing after and before reaching main(). Please see if you can perfrom the same debug steps that I suggested in the linked post.

Hope this helps.

Best Regards
Santosh Athuru