On Sat, Mar 01, 2014 at 03:27:56PM +0000, Grant Likely wrote:
Hi Christoffer. I've got another comment on the text, this time about the format of the ESP:
On Wed, 26 Feb 2014 10:34:54 -0800, Christoffer Dall christoffer.dall@linaro.org wrote: [...]
Image format
The image format, as presented to the VM, needs to be well-defined in order for prepared disk images to be bootable across various virtualization implementations.
The raw disk format as presented to the VM must be partitioned with a GUID Partition Table (GPT). The bootable software must be placed in the EFI System Partition (ESP), using the UEFI removable media path, and must be an EFI application complying to the UEFI Specification 2.4 Revision A [6].
The ESP partition's GPT entry's partition type GUID must be C12A7328-F81F-11D2-BA4B-00A0C93EC93B and the file system must be formatted as FAT32/vfat as per Section 12.3.1.1 in [6].
The removable media path is \EFI\BOOT\BOOTARM.EFI for the aarch32 execution state and is \EFI\BOOT\BOOTAA64.EFI for the aarch64 execution state.
I would also reference section 3.3 (Boot Option Variables Default Boot Behavior) and 3.4.1.1 (Removable Media Boot Behavior) here. It's fine to restate the meaning of the requirement in this spec, but the UEFI spec is the authoritative source. Distributed VM disk images fall under the same scenario as the firmware not having any valid boot variables.
ack, thanks.
-Christoffer