From b4dbbbdd97278c85862e274dcdd32b86eb39ae81 Mon Sep 17 00:00:00 2001
From: Stephan Raue <stephan@openelec.tv>
Date: Wed, 21 Nov 2012 16:08:10 +0100
Subject: [PATCH] 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>
---
 .../sysutils/busybox-initramfs/install         |  4 ++++
 .../sysutils/busybox-initramfs/scripts/init    | 18 +++++++++++++++++-
 projects/RPi/initramfs/initramfs.conf          |  4 ++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 projects/RPi/initramfs/initramfs.conf

diff --git a/packages/initramfs/sysutils/busybox-initramfs/install b/packages/initramfs/sysutils/busybox-initramfs/install
index edf12c5993..35bfb23c4f 100755
--- a/packages/initramfs/sysutils/busybox-initramfs/install
+++ b/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
diff --git a/packages/initramfs/sysutils/busybox-initramfs/scripts/init b/packages/initramfs/sysutils/busybox-initramfs/scripts/init
index b5eff1045d..16974a5ee0 100755
--- a/packages/initramfs/sysutils/busybox-initramfs/scripts/init
+++ b/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
diff --git a/projects/RPi/initramfs/initramfs.conf b/projects/RPi/initramfs/initramfs.conf
new file mode 100644
index 0000000000..c5c70d1494
--- /dev/null
+++ b/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