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Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 4ac2d641fcb6..b3bd36668db3 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt | |||
@@ -6,6 +6,8 @@ | |||
6 | IBM Corp. | 6 | IBM Corp. |
7 | (c) 2005 Becky Bruce <becky.bruce at freescale.com>, | 7 | (c) 2005 Becky Bruce <becky.bruce at freescale.com>, |
8 | Freescale Semiconductor, FSL SOC and 32-bit additions | 8 | Freescale Semiconductor, FSL SOC and 32-bit additions |
9 | (c) 2006 MontaVista Software, Inc. | ||
10 | Flash chip node definition | ||
9 | 11 | ||
10 | May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet. | 12 | May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet. |
11 | 13 | ||
@@ -1693,6 +1695,43 @@ platforms are moved over to use the flattened-device-tree model. | |||
1693 | }; | 1695 | }; |
1694 | }; | 1696 | }; |
1695 | 1697 | ||
1698 | g) Flash chip nodes | ||
1699 | |||
1700 | Flash chips (Memory Technology Devices) are often used for solid state | ||
1701 | file systems on embedded devices. | ||
1702 | |||
1703 | Required properties: | ||
1704 | |||
1705 | - device_type : has to be "rom" | ||
1706 | - compatible : Should specify what this ROM device is compatible with | ||
1707 | (i.e. "onenand"). Currently, this is most likely to be "direct-mapped" | ||
1708 | (which corresponds to the MTD physmap mapping driver). | ||
1709 | - regs : Offset and length of the register set (or memory mapping) for | ||
1710 | the device. | ||
1711 | |||
1712 | Recommended properties : | ||
1713 | |||
1714 | - bank-width : Width of the flash data bus in bytes. Required | ||
1715 | for the NOR flashes (compatible == "direct-mapped" and others) ONLY. | ||
1716 | - partitions : Several pairs of 32-bit values where the first value is | ||
1717 | partition's offset from the start of the device and the second one is | ||
1718 | partition size in bytes with LSB used to signify a read only | ||
1719 | partititon (so, the parition size should always be an even number). | ||
1720 | - partition-names : The list of concatenated zero terminated strings | ||
1721 | representing the partition names. | ||
1722 | |||
1723 | Example: | ||
1724 | |||
1725 | flash@ff000000 { | ||
1726 | device_type = "rom"; | ||
1727 | compatible = "direct-mapped"; | ||
1728 | regs = <ff000000 01000000>; | ||
1729 | bank-width = <4>; | ||
1730 | partitions = <00000000 00f80000 | ||
1731 | 00f80000 00080001>; | ||
1732 | partition-names = "fs\0firmware"; | ||
1733 | }; | ||
1734 | |||
1696 | More devices will be defined as this spec matures. | 1735 | More devices will be defined as this spec matures. |
1697 | 1736 | ||
1698 | 1737 | ||