yocto wic image generation for rz/g2ul board

Question

Hello Expert,

In yocto build of Renesas RZ/G2UL, it generates "tar.gz" image along with the bootloader and kernel images.

After that, we need to follow manual steps to partition the SD card and put the kernel and rootfs in seperate partition along with the DD of the bootloaders on initial sectors of SD card.

# sudo dd if=/dev/zero of=/dev/sda bs=1M status=progress

# ./usb_sd_partition.sh

# sudo dd if=bootparams-smarc-rzg2ul.bin of=/dev/sda seek=1 count=1
# sudo dd if=bl2-smarc-rzg2ul.bin of=/dev/sda seek=8
# sudo dd if=fip-smarc-rzg2ul.bin of=/dev/sda seek=128

# sudo cp Image-r9a07g043u11-smarc.dtb /media/embedded/RZ_FAT/
# sudo cp <Image>.bin /media/embedded/RZ_FAT/

# cd /media/embedded/RZ_ext/
# sudo tar jxvf <IMAGE>.tar.bz2

To avoid this manual process and do all the above processes in single common steps with command like "DD" (common way of other processor like NXP, TI ) way, do we have any WIC image generation WKS file?

How we can automate this process? (especially flash and prepare SD Card in Windows machine as well - with single wic or image file we can achieve that through different flash writer utility in Windows.)

A fast response would be appreciated.

Thanks and Regards,

Anil Patel

Chris · Accepted Answer

egret said: U-boot can load the kernel and device tree from an ext4 partition. Also, I don't think SMARC RZ/G2UL board and the software support anything that requires a FAT partition (e.g. UEFI). Why does it create a multi-partition image with a FAT partition? 
 
 The FAT partition is just to match the Renesas documentation and default boot commands of the Renesas Evaluation Boards. The FAT partition is helpful for people to add files that do not have a Linux PC. 
 The FAT partition is not required. I see many RZ products not include the FAT partition. They keep the files in /boot/ in ext4. 
 The image_creator script was created to make SD Card images to give to Renesas Sales people to program demos images into SD Cards using a Windows PC. But, it can be modified to however you want it. The important part is showing out to use loop mounts.

egret · Answer

Hi, 
 As the create_image.sh script in Chris's answer does, 
 
 By using a regular file instead of the special file (/dev/sda), you can create a WIC-like image file you need. 
 Like a SD card, a regular file can have multiple partitions, and each partition can be mounted using the loop device. 
 
 In your case, it seems that you are writing bootparams, BR2, and FIP to an unused area (?) right after the master boot record, so I think it would be faster to change your script than to change the create_image.sh script. 
 BR

yocto wic image generation for rz/g2ul board

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