[Freedos-kernel] Int21.7304.sf03 should actually copy/move FATs
Hi, the kernel is supposed to support all Int21.7304 (Set DPB/BPB fields for formatting) subfunctions but doesn't provide subfunction 03h completely. The current code simply gets (and sets as requested) the flags from the BPB, but doesn't move the FAT accordingly. MS-DOS apparently contains code to do so. This isn't documented in RBIL, but can be tested by setting the active FAT (of a FAT32 drive) to a single one, then resetting the flags to include all FATs later. The second call overwrites the previously inactive FAT(s) with a copy of the active one. (Depending on the size of the file system, this results in a short delay. If this isn't the case, files/directories can be created (changing FAT entries) while only the active FAT is used and dosfsck can be used to insure both FATs have the same content later when the flags were reset.) Regards, Christian -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] Int21.7304.sf03 should actually copy/move FATs
2009/8/6 Christian Masloch : > the kernel is supposed to support all Int21.7304 (Set DPB/BPB fields for > formatting) subfunctions but doesn't provide subfunction 03h completely. > The current code simply gets (and sets as requested) the flags from the > BPB, but doesn't move the FAT accordingly. MS-DOS apparently contains code > to do so. This isn't documented in RBIL, but can be tested by setting the > active FAT (of a FAT32 drive) to a single one, then resetting the flags to > include all FATs later. The second call overwrites the previously inactive > FAT(s) with a copy of the active one. (Depending on the size of the file > system, this results in a short delay. If this isn't the case, > files/directories can be created (changing FAT entries) while only the > active FAT is used and dosfsck can be used to insure both FATs have the > same content later when the flags were reset.) About a month ago I looked at the int21/ah=73 functions and there are a lot of corrections to make, mostly because RBIL is very brief in this area. I found this documentation which says more or less what you tell us too: http://www.thehackademy.net/madchat/vxdevl/vxmags/moonbug05/FAT32_32.HTM The links don't work without manually correcting URLs (case sensitivity!) but this looks like MSDN-style Microsoft documentation. Bart -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
[Freedos-kernel] new kernel released
The kernel developers have just finished up 2039 for release a few days ago (mostly bugfixes), so you can download it at ibiblio ( http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dos/kernel/2039/ or at sourceforge ( http://sourceforge.net/projects/freedos ) just wondering, why a) this wasn't advertised on this list and b) why there isn't a 386-fat32 binary available (hardly anyone even knows where he might see a real 8086 machine), and the 386 resident code is ~1,5 KB smaller Tom -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] Int21.7304.sf03 should actually copy/move FATs
Bart Oldeman wrote: > 2009/8/6 Christian Masloch : > >> the kernel is supposed to support all Int21.7304 (Set DPB/BPB fields for >> formatting) subfunctions but doesn't provide subfunction 03h completely. >> The current code simply gets (and sets as requested) the flags from the >> BPB, but doesn't move the FAT accordingly. MS-DOS apparently contains code >> to do so. This isn't documented in RBIL, but can be tested by setting the >> active FAT (of a FAT32 drive) to a single one, then resetting the flags to >> include all FATs later. The second call overwrites the previously inactive >> FAT(s) with a copy of the active one. (Depending on the size of the file >> system, this results in a short delay. If this isn't the case, >> files/directories can be created (changing FAT entries) while only the >> active FAT is used and dosfsck can be used to insure both FATs have the >> same content later when the flags were reset.) >> > > About a month ago I looked at the int21/ah=73 functions and there are > a lot of corrections to make, mostly because RBIL is very brief in > this area. > > I found this documentation which says more or less what you tell us too: > http://www.thehackademy.net/madchat/vxdevl/vxmags/moonbug05/FAT32_32.HTM > Yeah, the RBIL was mainly used as guide for development of FAT32 support, but MSDN was checked too, though RBIL was more complete on this topic at that time, dunno about MSDN's completeness at present time. We really need more complete docs on FAT32 to support it smoothly. Various bits of the info are spread over the internet here and there. Recovering the truth from these bits are very painful process. Victor Vlasenko -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
Re: [Freedos-kernel] new kernel released
On Thu, Aug 6, 2009 at 12:01 PM, Tom Ehlert wrote: *** SNIP *** > just wondering, why > > a) this wasn't advertised on this list and Oversight. > b) why there isn't a 386-fat32 binary available (hardly anyone even > knows where he might see a real 8086 machine), and the 386 resident code is > ~1,5 KB smaller Point out the file(s) that were missed and I'll do an update. If, in the future, you or any other kernel developer would like to write up a better announcement, feel free to do so and give it to me. I'll follow through. Thanks. Pat -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
