Date: Fri, 22 May 1998 14:01:46 -1000 From: "Randal S. Masutani" <randal@comtest.com> To: Mike Smith <mike@smith.net.au> Cc: freebsd-small@FreeBSD.ORG Subject: Re: Embeded applications? Message-ID: <199805222343.NAA07640@oldyeller.comtest.com> In-Reply-To: <199805222155.OAA02699@dingo.cdrom.com> References: Your message of "Fri, 22 May 1998 12:21:52 -1000." <199805222203.MAA07511@oldyeller.comtest.com>
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On 22 May 98 at 14:55, Mike Smith wrote: > > 1. Software BIOS emulation, INT 13H. Also identified as Flash File System. > > This mean that you can only access the flash through BIOS call interrupt 13H. > > Using INT 13H you can specify CHS(cylinder,head,sector) values to access the > > flash. It does not have any hardware compatibility with IDE I/O ports or > > registers. Since DOS commands rely only on BIOS calls to access hard drives, > > this type of emulation works with the standard DOS commands FDISK and FORMAT. > > FreeBSD kernel cannot see this type of flash since it cannot call BIOS > > routines. (this is the type of flash that is built onto the PC/104 CPU board I > > am using) > > Actually, FreeBSD-current probably *can* talk to this sort of flash > disk, although there are some missing components (the disk driver, eg.). > > Someone with a BIOS-only flash disk would be the perfect candidate to > complete this support. > > > I will try using the rawboot, since I do not need FFS. Technically I do not > > have access to FFS anyway as explained above, since I am using software BIOS > > flash drive. > > You can use the normal boot1/boot2 bootloaders, as they have enough FFS > support internally to read the kernel. I don't understand, do you mean that you can use FFS on a BIOS-only flash ? So boot1/boot2 will only make BIOS calls to access FFS on flash? If so then all I need to do is copy the boot image(with kernel/mfs and FFS) to flash? > > I still need to figure out once I have the kernel and MFS built. How to > > transfer that to the flash drive? I need some kind of program that > > can transfer an image to the flash drive using BIOS-INT 13H calls. > > Write the boot image to a floppy, boot DOS on the target system and use > diskcopy. This would be fine if the target system was a floppy disk. But the target system is emulating a BIOS hard drive. My understanding is diskcopy only works from floppy to floppy. > > This would be an alternative. Since I can format the flash drive as a > > bootable DOS FAT partition. And put the fbsdboot.exe and a bootable kernel > > image in it. And then boot DOS and have autoexec.bat execute fbsdboot.exe on > > startup. > > This wastes (lots of) space. Yes, although I have 8MB Flash memory to play with. > > NOTE: FYI, "FFS" acronyms is used in two ways. > > In FreeBSD FFS stands for Fast File System. > > In the PC/104 industry FFS stands for Flash File System. > > It can get confusing at times... :) > > Yes. Although the Flash File System extends beyond just the BIOS > interface. > > -- BTW, Mike the PC/104 board that I am using is from Mesa Electronics 4c27 which is using the Crystal CS8900 ethernet chip. Do you know if anyone is working on a driver for this chip? Randal Masutani ------------------------------------------------------------------------- ComTest Technologies, Inc. 3049 Ualena St., Suite 1005 Honolulu, Hawaii 96819 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
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