[ImageBuilder][PATCH] uboot-script-gen: Add virtio loader

[Pavel Zhukov <pavel@xxxxxxxxxxx>]

uboot supports virtio-blk drives and can load kernel image from it.
Adding option to use '-t virtio' for loading image from virtio device

Signed-off-by: Pavel Zhukov <pavel@xxxxxxxxxxx>
---
 README.md                | 14 +++++++-------
 scripts/uboot-script-gen |  3 +++
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index cb0cb13..64e62cd 100644
--- a/README.md
+++ b/README.md
@@ -267,9 +267,9 @@ Where:\
 -d specifies the "root" directory (paths in the config file are relative
    to it), this is not a working directory (any output file locations
    are specified in the config and any temporary files are in /tmp)\
--t specifies the u-boot command to load the binaries. "tftp", "sd", "usb"
-   and "scsi" are shorthands for "tftpb", "load mmc 0:1", "fatload usb 0:1"
-   and "load scsi 0:1", but actually any arbitrary command can be used,
+-t specifies the u-boot command to load the binaries. "tftp", "sd", "usb", 
"virtio"
+   and "scsi" are shorthands for "tftpb", "load mmc 0:1", "fatload usb 0:1",
+   "virtio load 0:1" and "load scsi 0:1", but actually any arbitrary command 
can be used,
    for instance -t "fatload" is valid.  The only special commands are:
    fit, which generates a FIT image using a script, and fit_std, which
    produces a standard style of fit image without a script, but has
@@ -339,10 +339,10 @@ Where:\
 -o specifies the output disk image file name\
 -a specifies whether the disk image size is to be aligned to the nearest
    power of two\
--t specifies the u-boot command to load the binaries. "tftp", "sd", "usb"
-   and "scsi" are shorthands for "tftpb", "load mmc 0:1", "fatload usb 0:1"
-   and "load scsi 0:1", but actually any arbitrary command can be used,
-   for instance -t "fatload" is valid.
+-t specifies the u-boot command to load the binaries. "tftp", "sd", "usb",
+   "virtio" and "scsi" are shorthands for "tftpb", "load mmc 0:1",
+   "fatload usb 0:1", "load virtio 0:1" and "load scsi 0:1", but actually
+   any arbitrary command can be used, for instance -t "fatload" is valid.
 
 
 disk\_image supports these additional parameters on the config file:
diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
index 7e5cc08..f07e334 100755
--- a/scripts/uboot-script-gen
+++ b/scripts/uboot-script-gen
@@ -1025,6 +1025,9 @@ while getopts ":c:t:d:ho:k:u:fp:" opt; do
         sd )
             load_opt="load mmc 0:1"
             ;;
+        virtio )
+            load_opt="load virtio 0:1"
+            ;;
         usb )
             load_opt="fatload usb 0:1"
             ;;
-- 
2.39.1