Create your OS MicroSD

Create your OS MicroSD

The OS MicroSD card will initially have a single partition on it that contains the UEFI firmware that can boot our RHEL9 iso. This can be the same MicroSD card you used to flash the bootloader or another one. You want something with reasonable capacity. I just googled 1TB SDXC cards are amazon.ca for $15CAD... just saying.

We can download the latest from the Pi Firmware Task Force github [releases](https://github.com/pftf/RPi4/releases). The pftf produces SBBR-compliant (UEFI+ACPI) AArch64 firmware for Raspberry Pi systems. At the time of this page the latest for the Pi4 is version 1.33 and that is what has been tested so far. I expect that later versions will not change the expected behaviour.

1. Download and extract the zip file in a suitable directory on your development workstation e.g. ~/Downloads/rpi4/firmware

     $ mkdir -p ~/Downloads/rpi4/firmware
     $ cd ~/Downloads/rpi4/firmware
     $ wget https://github.com/pftf/RPi4/releases/download/v1.33/RPi4_UEFI_Firmware_v1.33.zip
     $ unzip RPi4_UEFI_Firmware_v1.33.zip -d 1.33/

2. Format your MicroSD card so that it has a 200Mib FAT32 partition to hold the firmware. The remainder of the disk will host RHEL. I recommend a 128GB card minimum. Copy the extracted firmware to the new partition.

This assumes that /dev/sdb is the MicroSD card!!

     $ sudo sfdisk --delete /dev/sdb
     $ sudo sfdisk /dev/sdb <<EOF
       label: dos
       label-id: 0xcf1353bd
       device: /dev/sdb
       unit: sectors                    
       #blank line
       /dev/sdb1 : start=        2048, size=      409600, type=b
       EOF
     $ sudo mkfs -t vfat /dev/sdb1
     $ sudo mount /dev/sdb1 /mnt
     $ cp -rp  ~/Downloads/rpi4/firmware/1.33/* /mnt

3. Safely eject the MicroSD card and install it in your Pi4

No continue with copying the RHEL 9 iso to a separate USB disk that we will start the installation from.