From 7f058d61a10384ca81c88245c4ff80c08f89ad6b Mon Sep 17 00:00:00 2001 From: Benjamin Gilbert Date: Mon, 13 Nov 2017 11:25:04 -0800 Subject: [PATCH] disk_util: use FAT32 on ESP mkfs.vfat was defaulting to FAT16 based on the size of the partition. The UEFI spec (2.7 errata A, section 13.3) implies that only FAT32 is necessarily supported on the ESP, and we've received a report of hardware that doesn't recognize FAT16. --- build_library/disk_util | 3 +++ 1 file changed, 3 insertions(+) diff --git a/build_library/disk_util b/build_library/disk_util index a4a72b34d5..9c400c1cab 100755 --- a/build_library/disk_util +++ b/build_library/disk_util @@ -423,6 +423,9 @@ def FormatFat(part, device): cmd = ['mkfs.vfat'] if 'fs_label' in part: cmd += ['-n', part['fs_label']] + if part['type'] == 'efi': + # ESP is FAT32 irrespective of size + cmd += ['-F', '32'] Sudo(cmd + [device, vfat_blocks], stdout_null=True)