diff options
Diffstat (limited to 'Documentation/powerpc/booting-without-of.txt')
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 27b457c0972..b3bd36668db 100644 --- 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. @@ -33,13 +35,13 @@ - Change version 16 format to always align property data to 4 bytes. Since tokens are already aligned, that means no specific - required alignement between property size + required alignment between property size and property data. The old style variable alignment would make it impossible to do "simple" insertion of properties using memove (thanks Milton for noticing). Updated kernel patch as well - - Correct a few more alignement constraints + - Correct a few more alignment constraints - Add a chapter about the device-tree compiler and the textural representation of the tree that can be "compiled" by dtc. @@ -854,7 +856,7 @@ address which can extend beyond that limit. console device if any. Typically, if you have serial devices on your board, you may want to put the full path to the one set as the default console in the firmware here, for the kernel to pick - it up as it's own default console. If you look at the funciton + it up as its own default console. If you look at the function set_preferred_console() in arch/ppc64/kernel/setup.c, you'll see that the kernel tries to find out the default console and has knowledge of various types like 8250 serial ports. You may want @@ -1124,7 +1126,7 @@ should have the following properties: - interrupt-parent : contains the phandle of the interrupt controller which handles interrupts for this device - interrupts : a list of tuples representing the interrupt - number and the interrupt sense and level for each interupt + number and the interrupt sense and level for each interrupt for this device. This information is used by the kernel to build the interrupt table @@ -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. |