Embedded Development Tools

[littler]

Hi,all

Why does system.bit have the same size  as download.bit ?Isn't  download.bit generated by system.bit and *.elf?

 I converted the download.bit into *.mcs and downloaded it to spi/bpi flash.When power on and pressed the CPU_RESET_BUTTON,I didn't see any  output  through my UART or any leds twinkling.But in SDK,I ran my *.elf on the hardwre very well.How can I solidify  my software and hardware to the flash?

[iguo]

Bitstream size of a certain part is fixed. The elf content is integrated into the BRAM.

[gszakacs]

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iguo wrote:

Bitstream size of a certain part is fixed. The elf content is integrated into the BRAM.

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Just to clarify that, the system bitstream without the .elf integrated has a lot of zeroes in it where the

.elf would go in.  If your part supports bitstream compression, the download bitstream would

be larger after compression than the system bitstream.  However an uncompressed bitstream

is always the same length for the same target part.

-- Gabor

[hgleamon1]

What version of ISE are you using?

How did you generate your download.bit for conversion to an .mcs? Through XPS, through a command line or some other way?

How do you know that the download.bit you generated an .mcs from actually contains the .elf that you want to run?

Regards,

Howard

[littler]

Hi,Howard
I use ise13.4.Fisrt I generate hardware platporm in XPS.Second I generate my *.elf in SDK.Third I update the bitstream in XPS through combining system.bit and *.elf.Then I convert my download.bit into *.mcs by using impact tool in ise.In my opinion,system.bit represents the hardware,*.elf represents the software,bootload programm initials the system.What I want is to solidify my embeded system design to flash.I want some useful steps,because I am not sure I have done the matter in the right way.Do I make myself clearly?

[hgleamon1]

How do you specify the .elf in XPS?

I believe, in principle, your understanding of the .bit and .elf files is correct. However, I am not sure I understand you when you say the bootload program initialises the system. If you are specifying your own .elf, I do not think you need to include the bootloader as well. If you combine the .bit and .elf and convert that to an .mcs, the FPGA should configure (and execute) from the Flash without an external bootloader.

Regards,

Howard

[gszakacs · Accepted solution]

It's important to distigush the difference between a .elf file that will run from internal BRAM

and an .elf file that runs in external memory like DDR2 SDRAM.  If your program is small

enough to run in BRAM, then all you need is the merged .bit file.

If your .elf file is larger and runs from external memory, then you need to merge the bitloader

.elf with the .bit file and add your elf to the .mcs as a separate file using the offset address

required by the bit loader.

-- Gabor

[monali.sonawane]

hey, have you solved your problem?

If not I want to ask you one question, have you added your specific i.e.. "*.elf" file to you ISE project. Because if you have not merely update bitstream will not automatically take your specific elf file as input.

After updatebitstream check bitgen report in ISE project navigator and you will be able to check which elf it has taken. 

I know these steps are given nowhere but I raised a webcase for same problem and got the solution

All the best

[littler]

Hi monali
It's kind of u.I have solved the problem .Thank u anyway.

[tibacou]

Hey

I use the version 14.4 of tools of Xilinx I want know how merge the .bit and .elf in a same file ? I am doing project with sp605 I use the comande data2mem in order to have the file which contains the hw et sw. Then I use impact to generate the file .mcs and flash the sp605. In my terminal I don't have the sw who run. 

Best Regards.