How to execute code form inter RAM without JTAG?

Posted on May 17, 2011 at 13:26

Can't anybody answer my question?

Come on~

Posted on May 17, 2011 at 13:26

Hi all,

We can excute code in RAM with JTAG, and debug it

we only need to do flowing steps

1> Setup IROM1 start address: 0x20000000 size:0x3000

IRAM1 start address: 0x20003000 size:0x1000

2> Load Ram.ini file while debuging

===========================================

FUNC void Setup (void) {

SP = _RDWORD(0x20000000);

PC = _RDWORD(0x20000004);

_WDWORD(0xE000ED08, 0x20000000);

}

LOAD xxxx.axf INCREMENTAL

Setup();

g, main

===========================================

So, the programming is running in the interal ram

But, what I want to do is:

1> boot from system memory

2> communite with system bootloader and download program into ram

3> Excute GO command to execute code in the RAM

So, these are what I should do:

1> Setup IROM1 start address: 0x20000000 size:0x3000

IRAM1 start address: 0x20003000 size:0x1000

2> setup the Linker property page

R/O base: 0x20000200

R/W base: 0x20003000

3> Set vector table in ram:

NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x200);

4> Download program to 0x20000200 and execute GO command with this address

The turth is command is execeuted, but the program still not run

I have tried this way in flash memory, and successed

What I gonna do if I want to execute code in RAM memory?

Waiting for your help

:)

Posted on May 17, 2011 at 13:26

Do you use interrupts in the code? How do you setup the stack? How old is the MCU (rather, which version of bootloader?)

The bootloader

I can see that your SP is at beginning of RAM, it shall point to end of your RAM stack area instead!

Please try a simple loop with some LED blinking first.

Posted on May 17, 2011 at 13:26

Thank you for you replying!

Yes I use interrupts in the code

I try it in the flash memory in the same way and it success

I mean I setup the start address of the Flash as 0x08000000,

and set interrupt vector: NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0);

NVIC_VectTab_FLASH is defined with 0x08000000

For RAM memeory:

I also try execute GO command from address 0x20000200 + 4

and it still not work

BTW,the bootloader version is 2.1

How should setup SP?

Waiting for your help...

:)

Posted on May 17, 2011 at 13:26

Thank you for your reply

I really appreciate it

Could you specify the steps, I am a novice in this area

Thank you~

Posted on May 17, 2011 at 13:26

Hi scoollau,

I had tried a similar thing before. I'm not sure, but I think that you can't use the first 4KB/2KB of internal RAM for your code since this part is already used by the bootloader itself?

I think that you should set your IROM1 at something like 0x20001000 to avoid overwriting bootloader data. Am I right ?

Then, I think that when executing the GO command you should enter the start address not the SP address, (ie. 0x20001000 not (0x20001000 + 4)). that's what I've done anyway, and it seems working.

I hope it goes better for you :D