From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Marc-F. LUCCA-DANIAU" Subject: Re: What device for ROMFS ? Date: Sun, 22 Jan 2017 11:48:57 +0100 Message-ID: <4eaca2db-6121-3ca5-7d78-ea4da90bbced@gmail.com> References: <57433933.9070907@gmail.com> <5746A3A6.7010002@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:references:cc:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding; bh=IwVrNYTBNyhjOLj37pc7Rq+OluzozvwdnL2aaJMwwmQ=; b=Es/J9WVtOFAblvQMqmvj102Cx6ebREVfTbdAbd+UpX4M6t8VR61NynmgcLRH9QacVI Wi3DUk8w0kjWSiOt7BTAQaEydEl+jVJ5BykR8xQj0t+T1qY7YOJ2jwqs/9MsVDw2yVCT 2bONyvQME+jp8Sn0iL0/MBSpHfo81VHDqGS3S3EjcGTXtETHCjMogkerIsH3KFDQ5Fxw TPHzAyIfNiMNsO8MRw2hEQVB3uawiwVOlRqOAYFl1Pte5PiAXLawmRA7UIRF7UfOVKQK ZCM3Hafp6+i67AEiMRBdZNuW4+t5rzGQ1/8uvOCwrujSjzQ/thslTPPqvGjGxEu2dDkf nPxg== In-Reply-To: Sender: linux-8086-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="utf-8"; format="flowed" To: Cc: ELKS 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 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 >> 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 >> >>