Initramfs image for Hifive-unleashed board (fu540)

hello all,

I am following a yocto based build system to get the bootable image, but i am more curious about the initramfs image, we have a provision in the yocto that can we generate initramfs image ie cpio.gz format, so from now, how to put this image in sd card, and also spi-nor flash memory, i have observe that from sifive website , download the firmware code which is in gpt format, which has the fsbl and small recovery kernel+iniramfs image, is this possible to replicate the same thing from the initramfs image which is generated from the yocto build environment if so can anybody please help me about this.

Hi Rakesh,

I’m trying to interpret your request for information.

I understand that you’re working with HiFive Unleashed target platform and you are working with the freedom-u-sdk Open Embedded build ( Please correct me if I’m wrong.

One option for writing the initramfs to the SD card based off the freedom-u-sdk is using the command:
zcat demo-coreip-cli-freedom-u540.wic.gz | sudo dd of=/dev/sdX bs=512K iflag=fullblock oflag=direct conv=fsync status=progress

Writing the SPI-NOR flash on the HiFive Unleashed can be done with OpenOCD and the SiFive flash driver. An example of this can be found in the freedom-e-sdk.

If the above doesn’t help you, please provide additional clarifications on what you would like to do.

Hello Jim,

Yes, I am working with freedom-usdk for fu540 board , but I am not building customized demo-coreip-cli-freedom-usdk, instead of that I am using standard core-image-tiny-initramfs, a separate bb file available in yocto enviornment, from that am getting initramfs image as in cpio.gz format, so want to boot image from this.
How can I load this image to board.

And another concern is for example, firmaware code, which is available from sifive website, has both fsbl,and a small recovery kernel+roofs ie hifive-unleashed.gpt.
If we see the partition in this file using Fdisk,
We saw 2 partitions ,

  1. Fsbl

So I can get fsbl.bin by cross compiling opensource bootloader code.

And my concern is , I want to generate a initramfs, which is in 2nd partition, that to from cpio.gz image (which has built from yocto). Can I get any information about this.