Increase default amount of RAM for Base FVPs in FDTs

- Large RAM-disks may have trouble starting with 2GB of memory.
- Increase from 2GB to 4GB in FDT.

Change-Id: I12c1b8e5db41114b88c69c48621cb21247a6a6a7

docs/change-log.md

@@ -20,6 +20,10 @@ Detailed changes since last release
 *   Unmask SError and Debug exceptions in the trusted firmware.
     Also route external abort and SError interrupts to EL3.
 
+*   The amount of physical RAM available to Linux as specified in the FDTs for
+    Base FVPs have been increased from 2GB to 4GB. This resolves the issue of
+    failing to start user-space when using a RAM-disk file-system.
+
 
 ARM Trusted Firmware - version 0.2
 ==================================

docs/user-guide.md

@@ -338,10 +338,6 @@ To prepare a VirtioBlock file-system, do the following:
 
 ##### Prepare RAM-disk
 
-NOTE: The RAM-disk option does not currently work with the Linux kernel version
-described above; use the VirtioBlock method instead. For further information
-please see the "Known issues" section in the [Change Log].
-
 To prepare a RAM-disk root file-system, do the following:
 
 1.  Download the file-system image:

fdts/fvp-base-gicv2-psci.dts

@@ -115,10 +115,8 @@
 
 	memory@80000000 {
 		device_type = "memory";
-		reg = <0x00000000 0x80000000 0 0x80000000>;
+		reg = <0x00000000 0x80000000 0 0x80000000>,
-		/*
 		      <0x00000008 0x80000000 0 0x80000000>;
-		*/
 	};
 
 	gic: interrupt-controller@2f000000 {

fdts/fvp-base-gicv2legacy-psci.dts

@@ -115,10 +115,8 @@
 
 	memory@80000000 {
 		device_type = "memory";
-		reg = <0x00000000 0x80000000 0 0x80000000>;
+		reg = <0x00000000 0x80000000 0 0x80000000>,
-		/*
 		      <0x00000008 0x80000000 0 0x80000000>;
-		*/
 	};
 
 	gic: interrupt-controller@2c001000 {

fdts/fvp-base-gicv3-psci.dts

@@ -115,10 +115,8 @@
 
 	memory@80000000 {
 		device_type = "memory";
-		reg = <0x00000000 0x80000000 0 0x80000000>;
+		reg = <0x00000000 0x80000000 0 0x80000000>,
-		/*
 		      <0x00000008 0x80000000 0 0x80000000>;
-		*/
 	};
 
 	gic: interrupt-controller@2f000000 {