Re: [sqlite] Porting into a microcontroller, minimum requirements
Jay A. Kreibich wrote: > On Wed, May 07, 2008 at 10:25:49PM -0400, Andrew Cunningham scratched on the > wall: > > >> "I have doubts that you will be able to get SQLite to work on anything >> less than a 32-bit processor. >> D. Richard Hipp" >> > > >> I was under the impression as long as the processor had enough room to >> hold the program (and RAM) it would work. >> > > Yeah, but you have to compile it first... > > >> The difference I would have >> expected would simply be speed of execution, but eventually getting >> there. With simple inserts/queries and the speed of sqlite, I thought >> it should be okay. >> > > I suspect the issue has to do with 64-bit integer support. SQLite does > a lot with native 64-bit integer values (e.g. "unsigned long long int"). > Most 32-bit processors have instructions that can deal with 64 bit > values as single, whole values, even if they require a lot of > slight-of-hand behind the scenes. Even if the processor doesn't have > explicit instructions, the compiler can often fake it by using the > overflow bits and a lot of byte shuffling. > > I suppose it would be possible to play the same games with a 16 bit > (or even 8) processor, but I'm guessing the compilers for most of > these smaller chips don't support long long ints. Even if they do, > it is going to be pretty slow and inflate the code side. > > -j > > I once thought about trying to compile it with "cc65" to run on an Apple IIe, for fun. I then calculated that the Apple II doesn't have enough RAM in a flat address space. I then decided that I'd rather go outside and enjoy the sunshine. :) However... I still wonder if it would be possible. Maybe if the compile could automatically split the code into sections that could work like "overlays" did back in the Borland C/Pascal days on MS-DOS. But I suspect that memory access would be a problem I could also compile Sqlite into MIPS R2000, and write a small emulator to run on the Apple (that transparently handled bank-switching and paging RAM). That might work. Slowly... -- CONFIDENTIALITY NOTICE This electronic mail and the information contained herein are intended for the named recipient only. It may contain confidential, proprietary and/or privileged information. If you have received this electronic mail in error, please do not read any text other than the text of this notice and do not open any attachments. Also, please immediately notify the sender by replying to this electronic mail or by collect call to (262) 796-0925. After notifying the sender as described above, please delete this electronic mail message immediately and purge the item from the deleted items folder (or the equivalent) of your electronic mail system. Thank you. -- The above email disclaimer is required by our legal department. However, if you would like a more humorous disclaimer, check here: http://www-users.cs.york.ac.uk/susan/joke/disclaim.htm ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Porting into a microcontroller, minimum requirements
On Wed, May 07, 2008 at 10:25:49PM -0400, Andrew Cunningham scratched on the wall: > "I have doubts that you will be able to get SQLite to work on anything > less than a 32-bit processor. > D. Richard Hipp" > I was under the impression as long as the processor had enough room to > hold the program (and RAM) it would work. Yeah, but you have to compile it first... > The difference I would have > expected would simply be speed of execution, but eventually getting > there. With simple inserts/queries and the speed of sqlite, I thought > it should be okay. I suspect the issue has to do with 64-bit integer support. SQLite does a lot with native 64-bit integer values (e.g. "unsigned long long int"). Most 32-bit processors have instructions that can deal with 64 bit values as single, whole values, even if they require a lot of slight-of-hand behind the scenes. Even if the processor doesn't have explicit instructions, the compiler can often fake it by using the overflow bits and a lot of byte shuffling. I suppose it would be possible to play the same games with a 16 bit (or even 8) processor, but I'm guessing the compilers for most of these smaller chips don't support long long ints. Even if they do, it is going to be pretty slow and inflate the code side. -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "'People who live in bamboo houses should not throw pandas.' Jesus said that." - "The Ninja", www.AskANinja.com, "Special Delivery 10: Pop!Tech 2006" ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Porting into a microcontroller, minimum requirements
*snip* "I have doubts that you will be able to get SQLite to work on anything less than a 32-bit processor. D. Richard Hipp" I was under the impression as long as the processor had enough room to hold the program (and RAM) it would work. The difference I would have expected would simply be speed of execution, but eventually getting there. With simple inserts/queries and the speed of sqlite, I thought it should be okay. If I went with a 32 bit processor, would 512KB of flash and 32KB of RAM (same 2GB storage) be enough assuming I didn't perform huge queries? If I build without any OS, are there extra libraries that would be required? Andy ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Porting into a microcontroller, minimum requirements
At 02:43 07/05/2008, you wrote: >Hi, > >I was wondering if anyone has any basic guide lines on embedding SQLite into >a microcontroller. For example, I am considering using an 8/16 bit processor >with 1 MB flash, 1 MB SRAM and 2 GB data storage (SD card). Has anyone ported >this before to an embedded system without an OS? I have ported it to a 32bit. Take a look at contiki, it's a nano (femto) OS that works very well, is very portable and easy to add sqlite to it (in 32 bit world) >Thanks, >Andy L One reason that life is complex is that it has a real part and an imaginary part -Andrew Koenig ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Porting into a microcontroller, minimum requirements
On May 6, 2008, at 8:43 PM, Andrew Cunningham wrote: > Hi, > > I was wondering if anyone has any basic guide lines on embedding > SQLite into > a microcontroller. For example, I am considering using an 8/16 bit > processor > with 1 MB flash, 1 MB SRAM and 2 GB data storage (SD card). Has > anyone ported > this before to an embedded system without an OS? > I have doubts that you will be able to get SQLite to work on anything less than a 32-bit processor. D. Richard Hipp [EMAIL PROTECTED] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Porting into a microcontroller, minimum requirements
Hi, I was wondering if anyone has any basic guide lines on embedding SQLite into a microcontroller. For example, I am considering using an 8/16 bit processor with 1 MB flash, 1 MB SRAM and 2 GB data storage (SD card). Has anyone ported this before to an embedded system without an OS? Thanks, Andy ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
