This is the mail archive of the ecos-discuss@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

ROMRAM start for ARM


Hi Folks

Im trying to figure out how to make the ARM family ROMRAM start. In
particular im interested in the EBSA285.

I have to modify PLATFORM_SETUP1 so that after its setup the DRAM it
copies the image from ROM into RAM. My question is, what exactly do i
have to copy from where to where?

I need to copy the text, rodata sections. What about the rom_vectors
and fixed_vectors section? I assume these also need copying. It looks
like i just have to copy the image to address 0x0. 

I assume a ROMRAM application is linked using the RAM memory layout?
So all symbols will have the RAM values. How do i get the address the
code is currently in ROM? Does the linker know this or do i just have
to hard code it? It looks like the MIPs has the FLASH address
hardcoded into it. Is there is symbol i can use the find out how much
i have to copy? __rom_data_end?

At the moment it looks like i need to do the equivelent of
        memcpy(0,FLASH_START,__rom_data_end);
        goto ram
ram: nop;

Does this seem right?

       Thanks
                Andrew


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]