[PATCH openbmc 30/32] init: Add a hook to download files

[OpenBMC Patches]

From: "Milton D. Miller II" <miltonm at us.ibm.com>

Add a hook to run a shell command line that is stored in a u-boot
environment variable.  Only execute this command if the previously
established options file has a keyword trigger.  Do not even consider
the option if a build option flag is not set to y.

This allows one to specify at u-boot commands that would download
a read-only file system into memory for execution this boot instead
of needing to create a custom initramfs to netboot or specifing
debug-init-sh, entering the password, and doing the download from
the shell.

If the u-boot environment variable is empty or missing but both
the build variable is set and the keyword trigger are set print
a diagnostic message.  If the command fails invoke standard
debug_takeover for corrective action.

An example script:
fw_setenv openbmcinitdownload 'cp /proc/net/pnp /run/resolv.conf ; ln -snf ../run/resolv.conf /etc/resolv.conf ; wget -O /run/image-rofs http://server.example.com/path/image-test-rofs'
---
 .../obmc-phosphor-initfs/files/obmc-init.sh               | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-init.sh b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-init.sh
index 87f71e6..71a72fb 100644
--- a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-init.sh
+++ b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-init.sh
@@ -101,6 +101,7 @@ rwdev=/dev/mtdblock${rwfs#mtd}
 # Set to y for yes, anything else for no.
 force_rwfst_jffs2=y
 flash_images_before_init=n
+consider_openbmc_download_files=y
 
 rofst=squashfs
 rwfst=$(probe_fs_type $rwdev)
@@ -131,6 +132,20 @@ then
 	debug_takeover "Debug initial shell requested by command line."
 fi
 
+if test "x$consider_openbmc_download_files" = xy &&
+	grep -w openbmc-init-download-files $optfile
+then
+	echo "Executing download hook..."
+	cmd="$(get_fw_env_var openbmcinitdownload)"
+	if test -z "$cmd"
+	then
+		echo 2>&1 "Download command not found or empty, skipping."
+	elif ! sh -xc "$cmd"
+	then
+		debug_takeover "Download command '$cmd' failed."
+	fi
+fi
+
 # If there are images in root move them to /run/initramfs/ or /run/ now.
 imagebasename=${image##*/}
 if test -n "${imagebasename}" && ls /${imagebasename}* > /dev/null 2>&1
-- 
2.7.1