how to prevent boot region when program the sam4e using jtag

I am using at91sam4e16e and working on bootloader. boot region is defined at 0x400000 and application region is at 0x420000 onwards.

i have downloaded bootloader code into that region and compiled application code with 0x420000 link address. now I want to download that application to 0x420000 using Jtag but when I download it, all the memory goes erased and only application remains.

In avr, I could prevent the boot area in debugger option; How to do the same in sam4e?

regards, shreyas.

Solution

Go to project options.

In Debugger -> Images you can download extra image.

Note that I have only used this with the Debug info only-option enabled, but I have bundled bootloader with my app, so it is a bit different situation. (You can bundle bootloader in Linker -> Input tab.)

I also had a problem that since application wasn't in normal starting location, I had to initialize program counter, and stack pointer registers manually. You can do this by defining a macro file in Debugger -> Setup.

Macro file could look like this (note that this is for different MCU, so you may have different registers/addresses):

execUserReset() 
{
    // Set the stack pointer
    MSP = *(int*)0x00008000; 
    // Set the program counter
    PC = *(int*)0x00008004; 
}

This macro file skips bootloader when using debugger reset, but you could also make macro file which enters bootloader on reset by using different addresses.

Edit: Bundling the bootloader:

It's been a while since I have done this, so hopefully I remember everything.

You need to add your bootloader .bin file to Linker -> Input -> Raw binary image. Also define symbol bootloader, and section .bootloader. (I think alignment needs to be specified too, even if you use absolute placement.)

Add your bootloader symbol to Keep symbols: box above. This should make sure that bootloader is always included.

In your linker file, add line

place at address mem:0x00000000 { section .bootloader };

to place bootloader at specific address (change address to match your bootloader address).