On Fri, Jul 19, 2024 at 02:12:59PM +0000, Ghennadi Procopciuc wrote: > Greetings everyone, > > I came across the following paragraph while reading the 'Firmware Partition > Filesystem' chapter from EBBR v2.2.0 > and I would like to clarify my understanding: > Where possible, firmware images and data should be stored in a > filesystem. Firmware can be stored either in a > dedicated firmware partition, or in certain circumstances in the UEFI > System Partition (ESP). Using a filesystem > makes it simpler to manage multiple firmware files and makes it > possible for a single disk image to contain firmware > for multiple platforms. > > Dedicated firmware partitions should be formatted with a FAT filesystem > as defined in UEFI § 13.3 File System > Format. Dedicated firmware partitions should use the same /FIRMWARE > directory hierarchy. OS tools shall ignore > dedicated firmware partitions, and shall not attempt to use a dedicated > firmware partition as an ESP > > Questions: > 1. Does the above paragraph mean that, if the device allows, all firmware > binaries (TF-A, U-Boot, and some others) > must be stored in a dedicated firmware partition formatted with a FAT > filesystem and GUID Partition Table (GPT) > disk layout?
Hi Ghennadi, Yes, ideally this is what EBBR recommends as the second-best option (the best option being to use a dedicated storage). > 2. If so, would this also mean that, where possible, the BootROM or a > (first stage) bootloader running before TF-A > should have GPT and FAT support embedded support to load one of the > TF-A stages (BL1/BL2)? Yes. This is not as crazy as it sounds; I know some Texan SoCs from a decade ago, which had FAT + MBR support in ROM. Alternatively, U-Boot SPL as a first stage bootloader, as you mentioned, would tick all the boxes, too. This might be easier to fit in a small, dedicated storage. Best regards, Vincent Stehlé System Architect - Arm > > Regards, > Ghennadi > _______________________________________________ > boot-architecture mailing list -- boot-architecture@lists.linaro.org > To unsubscribe send an email to boot-architecture-le...@lists.linaro.org _______________________________________________ boot-architecture mailing list -- boot-architecture@lists.linaro.org To unsubscribe send an email to boot-architecture-le...@lists.linaro.org
