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> Append Nand Flash Partiton Info, Pass info to kernel via append
post Jun 14 2007, 07:10 AM
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Anyone know if it's possible to tell the kernel what the nand flash partition layout is trough an append statement from the boot loader ?

Currently u-boot sends this info to kernel:
console=ttyS0,115200 console=tty1 root=/dev/mtdblock2 rootfstype=jffs2

This only tels the kernel where the root is (nand partition 2) but the nand partition physical layout is hard coded to kernel.

Being able to pass the nand partition layout via boot loader would avoid :
having this info hard coded to kernel sources,
having to rebuild the kernel if you intend to make a different layout.

Ok this goes a bit off topik but is closely related:
Currently the u-boot image used with pdaxrom would need to be rebuilt in order to change this append info but this is not mandatory as u-boot is capable of reading stuff from virtually anywhere (including an ext3 or jffs2 filesystem) but would require work to make it functional on Z.

Currently uboot is being used at about 5% of it's capabilities as it would be possible to:
pick up a kernel from SD/MMC/CF/MicroDrive with fat or ext2 filesystem on it (and other filesystems to but probably not intresting for linux),
pick up the kernel from the jffs2 root image on the onboard nand,
pick up the boot configuration data (which kernel to boot from where and which root filesystem to use ... etc) from a file instead of having it hard coded to the sources (the file could be anywhere just like the kernel),
it could even be possible to have the video and keyboard working at boot time so that one could pass extra parameters without serial console (or doo some debugging without the serial console) like one can do with grub or any conventional boot loader for x86 linux.

All this could mean to a common user not having to flash anything in order to upgrade a kernel or have 2 different releases with 2 different kernels (including the more difficult combinations like beta3 and r198 or 2 different distributions) ... for any advanced user or developer ;-) well only immagination is the limit .

Am I the only one that would find this handy ?
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Posts in this topic
louigi600   Append Nand Flash Partiton Info   Jun 14 2007, 07:10 AM
louigi600   Ok this helps the append parameter: The format fo...   Jun 14 2007, 07:48 AM
louigi600   Ok I've a bit more info and a small correction...   Jun 14 2007, 11:40 PM
johnsutton   This is surely the right way to go. And maybe the...   Jun 15 2007, 03:38 AM
louigi600   QUOTE(johnsutton @ Jun 15 2007, 01:38 PM)This...   Jun 15 2007, 07:27 AM
johnsutton   Is beta1 on c1000 interesting? If so, you`ll ...   Jun 16 2007, 12:36 AM
louigi600   QUOTE(johnsutton @ Jun 16 2007, 10:36 AM)Is b...   Jun 16 2007, 12:46 AM
T3_slider   Here's my output from beta 3: CODELinux versi...   Jun 16 2007, 06:21 AM
pelrun   QUOTE(T3_slider @ Jun 16 2007, 02:21 PM)I hav...   Jun 16 2007, 05:10 PM
louigi600   The intresting information there is: CODESharp SL ...   Jun 16 2007, 12:03 PM
T3_slider   Actually it's a C3200 which is treated like a ...   Jun 16 2007, 06:31 PM
louigi600   QUOTE(pelrun @ Jun 17 2007, 03:10 AM)louigi60...   Jun 16 2007, 11:51 PM
pelrun   Ok, here's my Z's interesting bits (ooo er...   Jun 17 2007, 02:20 AM
louigi600   Intresting I did not notice that before .... beta3...   Jun 17 2007, 05:09 AM
pelrun   Can it be a kernel source trick? The values are de...   Jun 17 2007, 05:27 AM
louigi600   QUOTE(pelrun @ Jun 17 2007, 03:27 PM)Can it b...   Jun 17 2007, 08:40 AM
johnsutton   Here are two extracts from dmesg for beta1 running...   Jun 19 2007, 03:19 AM
louigi600   QUOTE(johnsutton @ Jun 15 2007, 01:38 PM)I...   Jun 19 2007, 06:56 AM
louigi600   Ok there is good chances that we could have kernel...   Jun 21 2007, 01:17 PM
johnsutton   Where would you plug in a serial cable? On a C100...   Jun 24 2007, 09:25 AM
louigi600   QUOTE(johnsutton @ Jun 24 2007, 07:25 PM)Wher...   Jun 24 2007, 09:58 AM
pelrun   The cxxxx's io port cap won't break if you...   Jun 24 2007, 08:18 PM
louigi600   QUOTE(pelrun @ Jun 25 2007, 06:18 AM)The cxxx...   Jun 25 2007, 10:56 AM
louigi600   Ok I've documented the cable on my home page a...   Jul 1 2007, 01:08 AM

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