Search found 34 matches
- Thu Aug 20, 2009 10:54 am
- Forum: Beginning OS Development
- Topic: What is wrong on some PC with this 1st stage BL?
- Replies: 12
- Views: 31624
Re: What is wrong on some PC with this 1st stage BL?
I found the solution: mov ax, 0x9000 ; set the stack <--- wrong As far as I see, this is in the root dir memory region (14 sectors; from 0x7E00 to 0x9A00) http://www.henkessoft.de/OS_Dev/Bilder/FAT1_FAT2_Root.PNG :shock: mov ax, 0x7C00 ; it works! The open question: Why does this mistake hit only on...
- Thu Aug 20, 2009 10:10 am
- Forum: Beginning OS Development
- Topic: What is wrong on some PC with this 1st stage BL?
- Replies: 12
- Views: 31624
Re: What is wrong on some PC with this 1st stage BL?
Can you successfully boot anything else off it? If I exchange my 1st stage BL with your original BL, then it works. I have read the original message again: "Loading Second Stage Bootloader " <-- this comes from mov [bootdevice], dl ; store boot device mov si, msgLoading call print_string Hence, it ...
- Thu Aug 20, 2009 9:53 am
- Forum: Beginning OS Development
- Topic: What is wrong on some PC with this 1st stage BL?
- Replies: 12
- Views: 31624
Re: What is wrong on some PC with this 1st stage BL?
This means that either the drive you are using is broken or the bootloader signature is in the wrong place I looked with a hex editor directly at the disk (in the floppy disk device of this PC): 0x55 0xAA at the right place (the same disk boots in other PCs). Looks like this: http://www.henkessoft....
- Thu Aug 20, 2009 8:02 am
- Forum: Beginning OS Development
- Topic: What is wrong on some PC with this 1st stage BL?
- Replies: 12
- Views: 31624
Re: What is wrong on some PC with this 1st stage BL?
This one (from 4) PC, which objects to boot process (whereas all the other three boot), tells me that there is "no bootable disk, press ... for reboot". I do not see the error possibility. Bootloading is a complex process, and you never know. BIOS int 0x18: ROM BASIC loader I have taken that from yo...
- Wed Aug 19, 2009 10:57 am
- Forum: Beginning OS Development
- Topic: What is wrong on some PC with this 1st stage BL?
- Replies: 12
- Views: 31624
What is wrong on some PC with this 1st stage BL?
To use an own BL is one of the great adventures in OS development, espacially if you want you OS running at all kinds of PC. I rearranged the BL of this demo, because I do not like org 0 and some of the variable names, but now on some modern PCs this BL does not start up: ; boot.asm [Bits 16] org 0x...
- Mon Aug 17, 2009 9:57 am
- Forum: Beginning OS Development
- Topic: OS Dev Demo11
- Replies: 7
- Views: 21496
Re: OS Dev Demo11
AFAIK, This would be a unique selling point. Great tutorial series! Please try to make it -Werror -Wall approved. Release Version of Demo15 could not be compiled error-free in MSVC++ 2008 Express, and a lot of errors appeared.to include USB booting
- Sun Aug 16, 2009 11:08 pm
- Forum: Beginning OS Development
- Topic: Questions about the future of the tutorial.
- Replies: 11
- Views: 31104
Re: Questions about the future of the tutorial.
Great! Thank you.
- Sun Aug 16, 2009 10:53 pm
- Forum: News Discussion
- Topic: something that we lost...
- Replies: 8
- Views: 63584
Re: something that we lost...
James Molloy's "heap" tutorial is quite good: http://www.jamesmolloy.co.uk/tutorial_h ... 0Heap.html
- Sun Aug 16, 2009 7:22 pm
- Forum: Beginning OS Development
- Topic: Chapter 20, Demo 15, how to write a sector to floppy disk?
- Replies: 6
- Views: 21186
Re: Chapter 20, Demo 15, how to write a sector to floppy disk?
http://www.dynacube.net/source/index.html
There you can find the interesting module floppy.h/floppy.c
Nice educational OS from India.
There you can find the interesting module floppy.h/floppy.c
Nice educational OS from India.
- Sun Aug 16, 2009 1:50 pm
- Forum: Beginning OS Development
- Topic: Demo 15 Problem
- Replies: 25
- Views: 70817
Re: Demo 15 Problem
OS code should run with -Werror and -Wall. Otherwise, there are a lot of hidden problems.I'm having a problem with the code in Demo 15
- Sun Aug 16, 2009 10:27 am
- Forum: Beginning OS Development
- Topic: Questions about the future of the tutorial.
- Replies: 11
- Views: 31104
Re: Questions about the future of the tutorial.
I would propose to read and write to USB sticks, because floppy discs are not widespread nowadays and will not be rampant in the future.
- Sun Aug 16, 2009 10:11 am
- Forum: Beginning OS Development
- Topic: Chapter 20, Demo 15, how to write a sector to floppy disk?
- Replies: 6
- Views: 21186
Re: Chapter 20, Demo 15, how to write a sector to floppy disk?
you should use FLPY_SECTORS_PER_TRACK as the parameter Yes, that's correct. In the beginning, I wanted to write a function void flpydsk_write_sector_imp(unsigned char head, unsigned char track, unsigned char sector, unsigned char num_of_sectors) It works wonderfully with num_of_sectors less than 18...
- Fri Aug 14, 2009 8:07 pm
- Forum: Beginning OS Development
- Topic: Chapter 20, Demo 15, how to write a sector to floppy disk?
- Replies: 6
- Views: 21186
Re: Chapter 20, Demo 15, how to write a sector to floppy disk?
current code: // write a sector void flpydsk_write_sector_imp(unsigned char head, unsigned char track, unsigned char sector) { ULONG st0, cyl; flpydsk_dma_write(); // set the DMA for write transfer flpydsk_send_command( FDC_CMD_WRITE_SECT | FDC_CMD_EXT_MULTITRACK | FDC_CMD_EXT_DENSITY ); // write a ...
- Fri Aug 14, 2009 8:01 pm
- Forum: Beginning OS Development
- Topic: 7c00
- Replies: 5
- Views: 17786
- Fri Aug 14, 2009 7:58 pm
- Forum: Beginning OS Development
- Topic: Chapter 20, Demo 15, how to write a sector to floppy disk?
- Replies: 6
- Views: 21186
Re: Chapter 20, Demo 15, how to write a sector to floppy disk?
This is nonsense:
better:
Code: Select all
flpydsk_send_command(( ( sector + 1 ) >= FLPY_SECTORS_PER_TRACK ) ? FLPY_SECTORS_PER_TRACK : sector + 1 );
Code: Select all
flpydsk_send_command( 18 );