What is the point of Booting From FPGA?

[Altera_Forum]

I'm reading all of the documentation on Cyclone V SOC and booting. Here's an Altera video: https://www.youtube.com/watch?v=yxwofue8ghw 

 Here's the Altera documentation: https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/hb/arria-10/a10_5400a.pdf  The video discusses the process where the second stage boot loader is loaded in FPGA RAM, which is on the other side of the HPS-FPGA bridge. But after the pre-loader is run from this RAM, the application is loaded from SD card. So why boot from the FPGA if you have an SD card? Why not just combine the preloader and app into the same SD card?   What I'm still trying to determine from all of the Altera documentation, is whether it is possible to:  1. Configure the FPGA from a QSPI attached to the FPGA Fabric (not the HPS QSPI) 2. Then have the HPS boot from the FPGA RAM which contains the pre-loader. 3. Then have the HPS load the application program from the FPGA QSPI  Any comments appreciated as I don't know where to turn to continue with this project. I'll have to move on to Xilinx or another solution (separate FPGA and processor). I've used Altera for over 20 years and the documentation continues to lack specifics.

[Altera_Forum]

You may want to have a look at www.rocketboards.org which is the right place for such things. 

 And yes, your approach seems to be applicable, but what do you mean with application in your 3.?  Do you mean the uboot, or a bare-metal-application?

[Altera_Forum]

Actually the intention is to demonstrate on how to create FPGA design that boot from FPGA 

Once the Preloader is boot up, Preloader can be used to load from anywhere as long as it can fit the FPGA RAM. In that sense, its possible to load from FPGA QSPI. Thanks to Thomas, the FPGA QSPI driver is upstreamed and available at http://git.denx.de/?p=u-boot.git;a=blob_plain;f=drivers/mtd/altera_qspi.c;hb=head

[Altera_Forum]

--- Quote Start ---  You may want to have a look at www.rocketboards.org (http://www.rocketboards.org) which is the right place for such things.  And yes, your approach seems to be applicable, but what do you mean with application in your 3.?  Do you mean the uboot, or a bare-metal-application?  --- Quote End ---     hello everyone please can you tell me how can i boot an RTOS on SD card to install in DE1 Soc without linux, I must have the control console of the kernel on VGA directly so that I can program after a machine control interface; thank's for you