git: bcf9147144f3 - main - EC2: Default to "uefi-preferred" boot mode

The branch main has been updated by cperciva:

URL: https://cgit.FreeBSD.org/src/commit/?id=bcf9147144f3499976a623f92712ecd0aca71912

commit bcf9147144f3499976a623f92712ecd0aca71912
Author:     Colin Percival <cperciva@FreeBSD.org>
AuthorDate: 2023-06-07 22:17:12 +0000
Commit:     Colin Percival <cperciva@FreeBSD.org>
CommitDate: 2023-06-14 18:31:10 +0000

    EC2: Default to "uefi-preferred" boot mode
    
    In EC2, UEFI boots faster than BIOS, but not all amd64 instance types
    support UEFI.  AMIs need to have their boot mode designated, which
    created a dilemma: Faster boots, or wider compatibility?
    
    The recently added "uefi-preferred" option solves this: AMIs can be
    marked to use UEFI where it's available, but fall back to BIOS on
    instance types which do not support UEFI.
    
    This uses bsdec2-image-upload 1.4.6, which recently landed in the
    ports tree.
    
    PR:             265697
    Reviewed by:    delphij, imp
    MFC after:      1 week
    Sponsored by:   https://www.patreon.com/cperciva
    Differential Revision:  https://reviews.freebsd.org/D40470
---
 release/Makefile.ec2 | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/release/Makefile.ec2 b/release/Makefile.ec2
index b29f54715fb3..e26f4f705cc6 100644
--- a/release/Makefile.ec2
+++ b/release/Makefile.ec2
@@ -25,11 +25,14 @@ SSMOPTS=	--ssm-name ${SSMPREFIX}/${TARGET_ARCH:S/aarch64/arm64/}/base/ufs/${REVI
 EC2ARCH=	--${TARGET_ARCH:S/aarch64/arm64/}
 .endif
 .if !defined(AMIBOOTMETHOD)
-AMIBOOTMETHOD=	UEFI
+AMIBOOTMETHOD=	UEFI-PREFERRED
 .endif
 .if ${AMIBOOTMETHOD} == "UEFI" && ${TARGET_ARCH} == "amd64"
 BOOTMODEOPT=	--uefi
 .endif
+.if ${AMIBOOTMETHOD} == "UEFI-PREFERRED" && ${TARGET_ARCH} == "amd64"
+BOOTMODEOPT=	--uefi-preferred
+.endif
 
 CLEANFILES+=		ec2ami