07-13-2015 06:14 AM
I have some questions.
According to the UG821,eMMC is a sencodary boot source. The boot image with FSBL is placed in the QSPI,and other required archives (U-boot, bit file, uImage,devicetree and ramdisk) are stitched an image and placed in eMMC.
1.What is the order of these archives in Bootgen? (bit file -> U-boot -> uImage -> devicetree -> RAMdisk or other squence)?
2. May I use SD card as a sencodary boot source in mini-itx board(FSBL in QSPI, other archives in SD card)?
PS. eMMC is placed at SD0 in our design.
07-13-2015 10:19 PM
Refer to the Prepare-Boot-Image page for details for order and creating BOOT.BIN.
Refer to Prepare-Boot-Medium for details on QSPI and SD card boot medium details.
07-15-2015 05:37 AM
Only a first stage bootloader needs to be in QSPI flash. Unless you use an eMMC controller in logic, because that would require the logic to be programmed before you can access it.
A second stage bootloader like u-boot in QSPI is convenient to use, since it runs a sort of shell on the serial port.
The bootloader can then access whatever devices it seems fit, you can boot the reset from NAND, SD, USB, or even Tizen's USB loader (send everything thru USB from a PC) if you have a recent u-boot. The bitstream, kernel and root filesystem can be placed on any of these devices.
07-22-2015 07:52 PM
I solved this problem finally.
First of all, the boot image(FSBL,bitstream and U-boot ) was placed in QSPI.
Second, uImage,devicetree and ramsidk were placed in eMMC.
PS. U-boot needed to modify as below:
07-23-2015 06:38 AM
Instead of modifying the source code, you could also have changed the u-boot environment.
"modeboot" is just an environment var. So is "qspiboot", and so is "sdboot".
And even with the standard Xilinx u-boot you can put an uEnv.txt file on the SD card, which can re-define qspiboot to do something different.