v0.666 - Now with new, extra evil features. And some dragons, probably.

TODO

@@ -1,12 +1,17 @@
 YES:
- * Downloading rootfs over http
  * Specifying rootfs location filesystem type
- * Other compression algorithms
  * Start different init than /sbin/init
  * Configuration examples, HOWTOs
- * Rootfs "overlays"/"parts"
+ * DNS configuration.
 
 MAYBE:
+ * Change the rootfs_part= argument handling, so that it would accept arbitrary
+    ammount of transformations; will lead to awesome stuff like transforming
+    next parts using scripts downloaded in previous parts.
  * Compression algorithm autodetection based on filename OR bsdtar automagic
  * Fancier OK/FAIL - at the end of the line, or somewhere
 
+DONE:
+ * Downloading rootfs over http
+ * Other compression algorithms
+ * Rootfs "overlays"/"parts"

initramfs/init

@@ -1,9 +1,15 @@
 #!/busybox sh
 
-NORMAL="\\033[0m"
-FAIL="\\033[1;31m"
-OK="\\033[1;32m"
-INFO="\\033[1;34m"
+NORMAL="\\033[0m" # white on black, or whatever your terminal is
+FAIL="\\033[1;31m" # red foreground
+OK="\\033[1;32m" # green foreground
+INFO="\\033[1;34m" # blue foreground
+
+alias tar='/busybox tar -C /roottmpfs -xpf -'
+alias bzcat='/busybox bzcat'
+alias xzcat='/busybox xzcat'
+alias mount='/busybox mount'
+alias umount='/busybox umount'
 
 die() {
     echo ""
@@ -46,29 +52,6 @@ info "mounting proc"
 /busybox mount -n -t proc proc ./proc
 isok $?
 
-# rootfs_location_uuid=f822d881-d88a-4200-a9cf-6986c5a3e69a
-info "looking for device with rootfs"
-for var in $(cat /proc/cmdline); do
-    if [[ ${var/=*} = rootfs_location_uuid ]]; then
-        uuid="${var/*=}"
-    fi
-done
-device=$(findfs UUID=${uuid})
-isok $?
-
-# rootfs_filename=rootfs.tar.xz
-info "getting rootfs filename"
-for var in $(cat /proc/cmdline); do
-    if [[ ${var/=*} = rootfs_filename ]]; then
-        filename="${var/*=}"
-    fi
-done
-if [[ -z ${filename} ]]; then
-    info "going with default: rootfs.tar.xz"
-    filename="rootfs.tar.xz"
-fi
-isok 0
-
 info "getting root tmpfs size"
 for var in $(cat /proc/cmdline); do
     if [[ ${var/=*} = rootfs_size ]]; then
@@ -81,25 +64,86 @@ if [[ -z ${size} ]]; then
 fi
 isok 0
 
-info "trying to mount ${device}"
-/busybox mount -n -o ro ${device} /mnt
-isok $?
-
 info "trying to mount root tmpfs"
 /busybox mount -n -o size=${size} -t tmpfs roottmpfs /roottmpfs
 isok $?
 
-info "checking if ${filename} exists"
-[[ -e /mnt/${filename} ]]
-isok $?
+info "checking if the user wants to use a different init"
+for var in $(cat /proc/cmdline); do
+    if [[ ${var/=*} = init ]]; then
+        init="${var/*=}"
+        info "user wants ${init}"
+    fi
+done
+if [[ -z "${init}" ]]; then
+    info "no; default: /sbin/init"
+    init="/sbin/init"
+    isok $?
+fi
 
-info "unpacking; will take some time"
+info "checking for network configuration on kernel commandline"
 echo ""
-/pv /mnt/${filename} | /busybox tar -C /roottmpfs -xJf -
+for var in $(cat /proc/cmdline); do
+    if [[ ${var/=*} = ipcmd ]]; then
+        # Split the "value" part of this parameter into parts, with "," as
+        # separators and then use them for constructing iproute2 commandline.
+        # Don't do any input validation; escape to the shell if things break.
+        # Do it in a subshell to prevent IFS change leak.
+        (
+            IFS=","
+            set -- ${var/*=}
+            info "ip ${@}"
+            /busybox ip ${@}
+            isok $?
+        )
+    fi
+done
 
-info "unmounting rootfs package location"
-/busybox umount -n /mnt
-isok $?
+# syntax examples:
+# rootfs_part=uuid|f822d881-d88a-4200-a9cf-6986c5a3e69a/some_directory/file|xzcat|tar
+#  -> findfs -> mount -> xzcat | tar
+# rootfs_part=url|http://10.3.13.37/url.tar.bz2|bzcat|tar
+#  -> wget -O - | bzcat | tar
+# You might find bugs & dragons here; patches accepted.
+info "looking for root filesystem tarballs"
+echo ""
+for var in $(cat /proc/cmdline); do
+    if [[ "${var/=*}" = rootfs_part ]]; then
+        part="${var/*=}"
+        info "found ${part}"
+        # uuid or url
+        url_type="${part/|*}"
+        # url + transformations
+        url="${part#${url_type}|}"
+        # transformations
+        transformations="${url#*|}"
+        # url
+        url="${url/|*}"
+        (
+            if [[ ${url_type} = "uuid" ]]; then
+                uuid="$(echo ${url} | /busybox cut -d / -f 1)"
+                filepath="${url#*/}"
+
+                info "mounting $(findfs UUID="${uuid}") on /mnt"
+                mount -n -o ro "$(findfs UUID="${uuid}")" /mnt
+                isok $?
+
+                info "unpacking /mnt/${filepath}"
+                echo ""
+                /pv "/mnt/${filepath}" | eval ${transformations}
+                isok $?
+
+                info "unmounting"
+                umount -n /mnt
+                isok $?
+            else
+                info "wgetting ${url} and transforming it on the fly"
+                /busybox wget -O - "${url}" | eval ${transformations}
+                isok $?
+            fi
+        )
+    fi
+done
 
 info "unmounting /dev"
 /busybox umount -n /dev
@@ -109,6 +153,10 @@ info "unmounting /proc"
 /busybox umount -n /proc
 isok $?
 
+info "checking if /roottmpfs/${init} exists"
+[[ -e /roottmpfs/${init} ]]
+isok $?
+
 info "trying to switch root"
 exec /busybox switch_root /roottmpfs /sbin/init