build: use 128MiB as the boot/kernel partition size on armvirt target

The nominal partition type for EFI boot partitions is FAT32,
which has a minimum size of 32MiB on a 512-byte-sector block device.

To ensure that the boot partition is created as FAT32 set a size
well above this minimum.

A useful discussion about EFI partition sizes can be found here:
https://superuser.com/questions/1310927/what-is-the-absolute-minimum-size-a-uefi-system-partition-can-be

I have found 128MiB works pretty consistently across both
tools (mkfs.fat) and firmwares (EDKII)

Signed-off-by: Mathew McBride <matt@traverse.com.au>

diff --git a/config/Config-images.in b/config/Config-images.in
index cbf1e9f26d6307d621ef4d2a0d97f3e9ffef58de..396f1dd3e3d1e7d8c48404090affb0ce063d6f91 100644 (file)
--- a/config/Config-images.in
+++ b/config/Config-images.in
@@ -292,6 +292,7 @@ menu "Target Images"
                depends on USES_BOOT_PART
                default 8 if TARGET_apm821xx_sata
                default 64 if TARGET_bcm27xx
+               default 128 if TARGET_armvirt
                default 16
 
        config TARGET_ROOTFS_PARTSIZE