> -----Original Message----- > From: Trent Piepho <tpie...@impinj.com> > Sent: Tuesday, July 17, 2018 10:24 AM > To: Henry Beberman <henry.beber...@microsoft.com>; u- > b...@lists.denx.de > Cc: tr...@konsulko.com; fabio.este...@nxp.com > Subject: Re: [U-Boot] [PATCH 01/11] imx: Add bootcmd to load and run UEFI > from mmc > > On Mon, 2018-07-16 at 23:56 +0000, Henry Beberman wrote: > > > > > > > > > > > I need to revise the commit message for this patch. The script is > > > > not fixed > > > > > > to the first partition of the selected MMC, it scans the disk for > > > partitions marked bootable, then checks each one of those until it > > > finds the imxboard_efi.fd binary. > > > > > > That is indeed very different from first FAT partition. Does > > > bootable only apply legacy MBR partition tables? I didn't think > > > bootable was typically used with GPT tables. There is a bit, but it's not > used to mark EFI partitions. > > > > > > Which brings me back to the partition type. Isn't that the right > > > way to find the EFI? > > > > The is_bootable function in disk/part_efi.c marks a partition as bootable if > the partition_type_guid on disk matches the EFI PARTITION_SYSTEM_GUID. > > The part command with the -bootable flag will return the EFI partition > > on both GPT and MBR partition schemes. This method is also used by > > config_distro_bootcmd.h > > But it also finds any partitions with the legacy bios bootable flag set in a > GPT > table or the active partition bit set in a MBR table, or any future reason a > partition might be considered bootable. Someone trying to add a new type > of bootable partition to distro bootcmd will be forced to deal with your > windows nt boot command as it tries to boot any bootable partition, even > ones it can't boot. > > The distro boot command is designed to boot anything, so it searches for > partitions beyond EFI. But what you've done is just for EFI. > That's why it's different.
It doesn’t matter if someone adds a new type of bootable partition in the future, the UEFI boot command will fail to find the imxboard_efi.fd binary then move along to check the next bootable partition. Adding this boot command will not increase maintenance on config_distro_bootcmd.h. The UEFI boot command is only used when the defconfig selects CONFIG_UEFI_BOOT, and the board's include/configs header has been modified to include config_uefi_bootcmd.h instead of config_distro_bootcmd.h when the config is set. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
