Date: Sun, 21 Nov 2010 15:18:45 +0800 From: Adrian Chadd <adrian@freebsd.org> To: Monthadar Al Jaberi <monthadar@gmail.com> Cc: freebsd-mips@freebsd.org Subject: Re: First RSPRO deployed ! Message-ID: <AANLkTim3s5oW=w3%2ByWFn6BwKq=UoCROnyfS4kgBm8-aD@mail.gmail.com> In-Reply-To: <AANLkTi=58UpFdeGybZqeA0eTugq-B6ebPQ7McPET1QMc@mail.gmail.com> References: <D74327E9-0A8A-4B46-B4DD-16D0FAF8E3BB@gmail.com> <CBBB7D88-210F-4706-A8FD-83FDA7EBA914@gmail.com> <AANLkTimAWM2UszxUsbnPkt0hra2pj0RqmbqhYMm7eCPv@mail.gmail.com> <201011191201.47230.freebsd-mips@dino.sk> <AANLkTi=58UpFdeGybZqeA0eTugq-B6ebPQ7McPET1QMc@mail.gmail.com>
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Nah, the problem is: * the large, fixed blocksize that the current flash code has; * ffs isn't really optimised for this kind of flash; * this kind of flash is will not like constant 4k erase cycles, which is unfortunately what you'll end up with. My current path forward is: * aim to get geom_ulzma into the base :-) * modify it a bit so it exports two GEOM devices - a read-only device with the lzma'ed FS in it, and a read-write'able "rest"; * modify GEOM to pass through disk parameters from the provider, so the flash device can export attributes (read size, write sizes, etc); * modify the flash driver to have a small default block size (say, 128 bytes) so small transactions don't require huge amounts of SPI bus access; * experiment with a simple append-only flash FS, which mounts on top of a read-only base filesystem. This mirrors what the flash device/fs stuff in linux does to some extent. The "rootfs" partition has a read only bit. Any filesystem modifications happen in the read-write part -after- that. If the user wants, they can simply erase the rootfs part -after- the read-only lzma'ed FFS partition, giving them a clean "default" system. If someone else wants to give this a go, be my guest. :-) Adrian On 19 November 2010 19:06, Monthadar Al Jaberi <monthadar@gmail.com> wrote: > On Fri, Nov 19, 2010 at 12:01 PM, Milan Obuch <freebsd-mips@dino.sk> wrote: >> On Thursday 18 November 2010 13:43:51 Monthadar Al Jaberi wrote: >>> OMG, thank you Luiz for the file.... Adrian forgot to mention that you >>> need to add kern_memstart field to the fw_layout_data structure!!! >>> >>> Its works...so I guess to boot from flash we need to play with the >>> flash driver and ffs... thats a totally different story though :P >>> >> >> Well, with mkfwimage it is possible to write FreeBSD into flash on RSPRO and >> boot from it. I just verified this. Using it the way it's used in mkflash >> script has one drawback, I think - your setup is static and you are not using >> whole flash to its best potential as well. Actually, with patches you are able >> to read flash (verified) and probably write to it, too, so the 'only' >> remaining part is ffs tuned to use it... > > mm, as I understood it it should be easy for ffs2 to work, just need > to fix some macros so that the code that probes for the superblock > work... > reading/writting to flash with correct sectorsize is no problem.... > >> >> Regards, >> Milan >> > > > > -- > //Monthadar Al Jaberi > _______________________________________________ > freebsd-mips@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-mips > To unsubscribe, send any mail to "freebsd-mips-unsubscribe@freebsd.org" >
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