Merge ../linus

[linux-drm-fsl-dcu.git] / Documentation / powerpc / booting-without-of.txt

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 4ac2d641fcb6a9b848fdb3c0761ea57b0ec25cb4..b3bd36668db3a4cef12a7996dfb51f78180da129 100644 (file)
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -6,6 +6,8 @@
     IBM Corp.
 (c) 2005 Becky Bruce <becky.bruce at freescale.com>,
     Freescale Semiconductor, FSL SOC and 32-bit additions
+(c) 2006 MontaVista Software, Inc.
+    Flash chip node definition
 
    May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet.
 
@@ -1693,6 +1695,43 @@ platforms are moved over to use the flattened-device-tree model.
                };
        };
 
+    g) Flash chip nodes
+
+    Flash chips (Memory Technology Devices) are often used for solid state
+    file systems on embedded devices.
+
+    Required properties:
+
+     - device_type : has to be "rom"
+     - compatible : Should specify what this ROM device is compatible with
+       (i.e. "onenand"). Currently, this is most likely to be "direct-mapped"
+       (which corresponds to the MTD physmap mapping driver).
+     - regs : Offset and length of the register set (or memory mapping) for
+       the device.
+
+    Recommended properties :
+
+     - bank-width : Width of the flash data bus in bytes. Required
+       for the NOR flashes (compatible == "direct-mapped" and others) ONLY.
+     - partitions : Several pairs of 32-bit values where the first value is
+       partition's offset from the start of the device and the second one is
+       partition size in bytes with LSB used to signify a read only
+       partititon (so, the parition size should always be an even number).
+     - partition-names : The list of concatenated zero terminated strings
+       representing the partition names.
+
+   Example:
+
+       flash@ff000000 {
+               device_type = "rom";
+               compatible = "direct-mapped";
+               regs = <ff000000 01000000>;
+               bank-width = <4>;
+               partitions = <00000000 00f80000
+                             00f80000 00080001>;
+               partition-names = "fs\0firmware";
+       };
+
    More devices will be defined as this spec matures.