From: "Marc-F. LUCCA-DANIAU" <mfld.fr@gmail.com>
To: ELKS <Linux-8086@Vger.Kernel.Org>
Subject: Re: What device for ROMFS ?
Date: Mon, 23 Jan 2017 20:48:02 +0100 [thread overview]
Message-ID: <51266403-f3b9-972c-f742-157e5b136aed@gmail.com> (raw)
In-Reply-To: <CACpuWUnkJ01bXDfTCSPS5_VfWHL+gca9=pixfM-YGG+_Mnob5A@mail.gmail.com>
Not forgotten and tracked by :
https://github.com/mfld-fr/elks/issues/2
MFLD
>
> Le 27/05/2016 à 00:36, Juan Perez-Sanchez a écrit :
>>
>> Looks good. That would be an interesting contribution to this project.
>> Later, you could add Execute In Place (XIP) to this modified ROMFS.
>>
>> Juan
>>
>>
>> On Thu, May 26, 2016 at 2:20 AM, Marc-F. LUCCA-DANIAU <mfld.fr@gmail.com>
>> wrote:
>>>
>>> Thanks Juan for that info.
>>>
>>> It helped me to find some missing #define in the setup configuration
>>> reading.
>>> I will commit the related fixes later (because not so many people using
>>> ROM
>>> boot for ELKS :-)).
>>>
>>> Coding a fresh new block device is one solution, but the ROM is by nature
>>> a
>>> flat and linear device (except when erasing / writting).
>>>
>>> So I would rather refactor the existing ROMFS to directly pick data from
>>> a
>>> given area in the ROM, and that area to be described in the ELKS config,
>>> like the other ROM options.
>>>
>>> Does it make sense ?
>>>
>>> MFLD
>>>
>>>
>>> Le 24/05/2016 01:07, Juan Perez-Sanchez a écrit :
>>>
>>> Hello:
>>>
>>> For the standard case, the root device is defined by the
>>> arch/i86/tools/build program (see Documentation/text/boot.txt). The
>>> device number is saved in bytes 508,509 of boot sector.
>>>
>>> After booting, the root device number is read from that location into
>>> the ROOT_DEV variable by the function setup_arch() in
>>> arch/i86/kernel/system.c.
>>>
>>> Maybe the mkbootloader does not define the root device as expected by
>>> the kernel.
>>>
>>> In addition, you will have to write a ROM block device driver. Also, I
>>> think romfs for ELKS never reached a working status.
>>>
>>> Juan
>>>
>>>
>>> On Mon, May 23, 2016 at 12:09 PM, Marc-F. LUCCA-DANIAU
>>> <mfld.fr@gmail.com> wrote:
>>>
>>> Hello,
>>>
>>> In a few words: what is the device to be used for a ROMFS root ?
>>>
>>> More: I configured ELKS as a ROM image for an embedded system, and I run
>>> it
>>> under EMU86, but I cannot figure out:
>>>
>>> 1- how to tell ELKS to read the ROMFS superblock from ROM address space?
>>> 2- how to build a ROMFS image to put in the ROM address space?
>>>
>>> All my tries end up with the well known:
>>>
>>> $ ./emu86 -w 0xe0000 -f ../../elks/elks/arch/i86/Image -x 0xe000:0x42 -i
>>>
>>> $ ./pcat `cat emu86.pts`
>>> Loading kernel image...
>>> Console: BIOS 10x115 emulating ANSI (3 virtual consoles)
>>> PC/AT class machine, inode! CPU8308K base RAM, CPUID `nd socket for in'.
>>> ELKS kernel (39008 text + 4168 data + 48648 bss)
>>> Kernel text at e062:0000, data at 90:0000 62 K of memory for user
>>> processes.
>>> ELKS network sockets
>>> TCP/IP stack by Harry Kalogirou
>>> ELKS version 0.2.0
>>> panic: VFS: Unable to mount root fs on 206D
>>> apparent call stack:
>>> Line: Addr Parameters~~~~: ~~~~ ~~~~~~~~~~
>>> 0: 1D59 => 0000 7102 0000 0000 0000 0000 0000
>>> 1: 00B7 => 0000 0000 0000 0000 0000 0000 0000
>>> 2: 0000 => CE50 0000 0000 0001 0000 6166 6C69
>>> 3: 1048 => 0000 0000 0000 0000 0000 0000 0000
>>> 4: 0000 => CE50 0000 0000 0001 0000 6166 6C69
>>> 5: 1048 => 0000 0000 0000 0000 0000 0000 0000
>>> 6: 0000 => CE50 0000 0000 0001 0000 6166 6C69
>>> 7: 1048 => 0000 0000 0000 0000 0000 0000 0000
>>> 8: 0000 => CE50 0000 0000 0001 0000 6166 6C69
>>> SYSTEM LOCKED - Press CTRL-ALT-DEL to reboot:
>>>
>>> Any suggestion ?
>>>
>>> Thanks,
>>>
>>> MFLD
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-8086" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>>
>
next parent reply other threads:[~2017-01-23 19:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CACpuWUnkJ01bXDfTCSPS5_VfWHL+gca9=pixfM-YGG+_Mnob5A@mail.gmail.com>
2017-01-23 19:48 ` Marc-F. LUCCA-DANIAU [this message]
2017-04-10 19:07 ` What device for ROMFS ? - Try booting a minix hard disk image on the flash disk G. Potthast
[not found] ` <CACpuWUnuXdvP5hAt4OicJG59NyNeOUReW+qXCvadwRb2ebgOYQ@mail.gmail.com>
2017-04-10 19:53 ` Marc-François LUCCA-DANIAU
2017-04-14 20:41 ` Run ELKS using a Javascript or Java based PC emulator Georg Potthast 2
2016-05-23 17:09 What device for ROMFS ? Marc-F. LUCCA-DANIAU
2016-05-23 23:07 ` Juan Perez-Sanchez
[not found] ` <5746A3A6.7010002@gmail.com>
2016-05-26 7:22 ` Marc-François LUCCA-DANIAU
[not found] ` <CAMKR1yu1nyCysPrwTubBF8VBBOJ_4u6vSQnD7R7h_nMmJeOfWg@mail.gmail.com>
2016-05-26 12:11 ` Marc-François LUCCA-DANIAU
2016-05-26 12:33 ` One Thousand Gnomes
2016-05-26 22:36 ` Juan Perez-Sanchez
2017-01-22 10:48 ` Marc-F. LUCCA-DANIAU
2017-01-22 13:23 ` Marc-François LUCCA-DANIAU
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