busybox-initramfs: copy SYSTEM to RAM before mounting. this new feature can be deactivated with the 'noram' option to the bootloaderconfig or is not avaible if to avaible total memory (1024000 Kb on normal systems, 364544 Kb for RaspberryPi) is to low.

Signed-off-by: Stephan Raue <stephan@openelec.tv>

packages/initramfs/sysutils/busybox-initramfs/install

@@ -31,6 +31,10 @@ mkdir -p $INSTALL/etc
   touch $INSTALL/etc/fstab
   ln -sf /proc/self/mounts $INSTALL/etc/mtab
 
+  if [ -f $PROJECT_DIR/$PROJECT/initramfs/initramfs.conf ]; then
+    cp $PROJECT_DIR/$PROJECT/initramfs/initramfs.conf $INSTALL/etc
+  fi
+
 mkdir -p $INSTALL/dev
 mkdir -p $INSTALL/proc
 mkdir -p $INSTALL/sys

packages/initramfs/sysutils/busybox-initramfs/scripts/init

@@ -81,6 +81,9 @@ NBD_DEVS="0"
       nosplash)
         SPLASH=no
         ;;
+      noram)
+        SYSTEM_TORAM=no
+        ;;
       overlay)
         OVERLAY=yes
         ;;
@@ -458,7 +461,20 @@ NBD_DEVS="0"
 
     if [ -f "/flash/$IMAGE_SYSTEM" ]; then
     # /flash is filesystem with system image file
-      mount_part "/flash/$IMAGE_SYSTEM" "/sysroot" "ro,loop"
+      INSTALLED_MEMORY=`cat /proc/meminfo | grep 'MemTotal:' | awk '{print $2}'`
+      SYSTEM_TORAM_LIMIT=1024000
+
+      if [ -f "/etc/initramfs.conf" ]; then
+        . /etc/initramfs.conf
+      fi
+
+      if [ "$SYSTEM_TORAM" = "no" -o "$INSTALLED_MEMORY" -lt "$SYSTEM_TORAM_LIMIT" ]; then
+        mount_part "/flash/$IMAGE_SYSTEM" "/sysroot" "ro,loop"
+      else
+        cp /flash/$IMAGE_SYSTEM /dev/$IMAGE_SYSTEM
+        mount_part "/dev/$IMAGE_SYSTEM" "/sysroot" "ro,loop"
+      fi
+
       /bin/busybox mount --move /flash /sysroot/flash
     else
     # /flash is actual root filesystem

projects/RPi/initramfs/initramfs.conf

@@ -0,0 +1,4 @@
+# min size to support System to RAM
+# default for RaspberryPi we set to 356MB (256MB + appr. image size (100MB) )
+# to be sure we have at least 256MB free
+  SYSTEM_TORAM_LIMIT=364544