From: Marian Balakowicz <m8@semihalf•com>
To: Grant Likely <grant.likely@secretlab•ca>
Cc: linuxppc-dev@ozlabs•org, Martin Krause <Martin.Krause@tqs•de>
Subject: Re: [PATCH 05/11] [POWERPC] TQM5200 DTS
Date: Thu, 25 Oct 2007 17:46:19 +0200 [thread overview]
Message-ID: <4720BA4B.5090707@semihalf.com> (raw)
In-Reply-To: <fa686aa40710250653o6e7df26y1890d5c485a6d508@mail.gmail.com>
Grant Likely wrote:
> On 10/25/07, Martin Krause <Martin.Krause@tqs•de> wrote:
>>
>> < + flash@00000000 {
>> < + compatible = "cfi-flash";
>> < + reg = <00000000 02000000>;
>> < + bank-width = <4>;
>> < + device-width = <2>;
>> < + #size-cells = <1>;
>> < + #address-cells = <1>;
>> < + partition@0 {
>> < + label = "firmware";
>> < + reg = <0 a0000>;
>> < + };
>> < + partition@a0000 {
>> < + label = "dtb";
>> < + reg = <a0000 20000>;
>> < + };
>> < + partition@c0000 {
>> < + label = "kernel";
>> < + reg = <c0000 240000>;
>> < + };
>> < + partition@300000 {
>> < + label = "initrd";
>> < + reg = <300000 200000>;
>> < + };
>> < + partition@500000 {
>> < + label = "small-fs";
>> < + reg = <500000 400000>;
>> < + };
>> < + partition@900000 {
>> < + label = "misc";
>> < + reg = <900000 800000>;
>> < + };
>> < + partition@1100000 {
>> < + label = "big-fs";
>> < + reg = <1100000 f00000>;
>> < + };
>> < + };
>> < + };
>>
>> This MTD layout only works on boards with 32 MiB (or 64 MiB) flash
>> memory. On TQM5200 boards with smaller Flashes (16 MiB, 8 MiB and 4 MiB)
>> the MTD partition borders do not match with the physikal memory borders.
>
> If there is a variant board with a different configuration, then the
> device tree needs to be changed for that variant board; either by
> having multiple .dts files in arch/powerpc/boot/dts or by having the
> bootloader populate the correct information. A dtb as passed to the
> kernel must exactly represent the hardware.
>
> That also means that there is going to be a different flash map for
> each possible flash size configuration.
Agree, that's one particular configuration (I guess I should add
proper comment), that should be updated if needed. But I'am not sure
if we should have multiple .dts files if it's only flash layout that
changes.
>> On a board with 16 MiB FLASH for example the "big-fs" _and_ the "misc"
>> partition could not be used. "big-fs", because the memory is too small
>> (which is OK) and "misc", because it overlaps 1 MiB over the physikal
>> flash border. So only the first 9 MiB of the flash could be used in Linux.
>> The remaining 7 MiB couldn't be accessed.
>
> Perhaps it would be better to drop the flash layout from the in-kernel
> dts files entirely since flash layout can be a fluid thing.
Well, but that would not be really user friendly, I'd rather stick
with some default config.
m.
next prev parent reply other threads:[~2007-10-25 15:46 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-23 23:13 [PATCH 00/11] [POWERPC] Add TQM5200/CM5200/Motion-PRO board support Marian Balakowicz
2007-10-23 23:13 ` [PATCH 01/11] [POWERPC] Add 'machine: ...' line to common show_cpuinfo() Marian Balakowicz
2007-10-23 23:23 ` David Gibson
2007-10-25 14:17 ` Marian Balakowicz
2007-10-23 23:59 ` Olof Johansson
2007-10-24 7:11 ` Stephen Rothwell
2007-10-25 4:33 ` Milton Miller
2007-10-25 14:47 ` Marian Balakowicz
2007-10-23 23:13 ` [PATCH 02/11] [POWERPC] Add 'lpb' bus type for MPC5200 LocalPlus Bus Marian Balakowicz
2007-10-24 0:09 ` Olof Johansson
2007-10-25 14:55 ` Marian Balakowicz
2007-10-23 23:13 ` [PATCH 03/11] [POWERPC] Add common mpc52xx_setup_pci() routine Marian Balakowicz
2007-10-24 7:16 ` Stephen Rothwell
2007-10-23 23:13 ` [PATCH 04/11] [POWERPC] Add generic support for MPC5200 based boards Marian Balakowicz
2007-10-24 14:03 ` Grant Likely
2007-10-23 23:13 ` [PATCH 05/11] [POWERPC] TQM5200 DTS Marian Balakowicz
2007-10-24 1:51 ` David Gibson
2007-10-24 14:09 ` Grant Likely
2007-10-25 15:23 ` Marian Balakowicz
2007-10-25 9:57 ` Martin Krause
2007-10-25 13:53 ` Grant Likely
2007-10-25 15:46 ` Marian Balakowicz [this message]
2007-10-26 1:33 ` David Gibson
2007-10-29 14:18 ` Marian Balakowicz
2007-10-29 15:40 ` Grant Likely
2007-10-30 0:58 ` David Gibson
2007-10-30 5:58 ` Grant Likely
2007-10-30 15:34 ` Marian Balakowicz
2007-10-23 23:13 ` [PATCH 06/11] [POWERPC] TQM5200 defconfig Marian Balakowicz
2007-10-23 23:13 ` [PATCH 07/11] [POWERPC] CM5200 DTS Marian Balakowicz
2007-10-23 23:13 ` [PATCH 08/11] [POWERPC] CM5200 defconfig Marian Balakowicz
2007-10-23 23:13 ` [PATCH 09/11] [POWERPC] Motion-PRO: Add LED support Marian Balakowicz
2007-10-24 14:18 ` Grant Likely
2007-10-25 15:53 ` Marian Balakowicz
2007-10-23 23:14 ` [PATCH 10/11] [POWERPC] Promess Motion-PRO DTS Marian Balakowicz
2007-10-23 23:14 ` [PATCH 11/11] [POWERPC] Promess Motion-PRO defconfig Marian Balakowicz
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