[Freedos-devel] CPU flags register not updating on interrupt calls

Hi, everyone. I’m new here. This is my first post.  I am currently working on getting FreeDOS running on my homebrew 286 system. I am running into an issue where interrupt calls from FreeDOS to my BIOS are not showing updated values for the CPU flags register after the call. This happens

Re: [Freedos-devel] CPU flags register not updating on interrupt calls

Not sure if it’s bad etiquette to reply to your own post, but… I may just need to change out my “iret” with “ret 2”. I’m doing some testing… Rich From: rehsd.i...@gmail.com Sent: Sunday, April 30, 2023 4:53 PM To: freedos-devel@lists.sourceforge.net Subject: CPU flags register not

Re: [Freedos-devel] CPU flags register not updating on interrupt calls

I ended up with "retf 2" and it seems to be working fine. I will see if I can switch out the retf 2 with stack frame manipulation, like you show. Thanks! Rich -Original Message- From: C. Masloch Sent: Monday, May 1, 2023 3:31 AM To: freedos-devel@lists.sourceforge.net Subject: Re:

[Freedos-devel] struct alignment issue?

In initdisk.c [1], there is a label "StandardBios:" at line 719. In the code at this location, FreeDOS makes an INT13H function 0x08 call to get current drive parameters. The values of the drive parameters are then parsed out of the return registers and placed into

Re: [Freedos-devel] struct alignment issue?

I may have narrowed down the issue to a hardware-related problem. I am going to do some further testing in that direction and post an update as I know more. From: rehsd.i...@gmail.com Sent: Sunday, May 28, 2023 1:48 PM To: freedos-devel@lists.sourceforge.net Subject: struct alignment issue?

Re: [Freedos-devel] trying to understand execrh.asm -- calls to EXECRH cause my 286 system to lock up

Thank you, ecm! The information you provided has been very helpful. I have been able to insert debug output in the driver to better troubleshoot. Related, I am now reading "Advanced MSDOS Programming" from Microsoft Press, and I'm finding it quite helpful. Little by little, I'm making progress.

Re: [Freedos-devel] trying to understand execrh.asm -- calls to EXECRH cause my 286 system to lock up

Thank you, Eric! -I will do some testing of reading the CF card outside of the FreeDOS kernel, as you suggest. -My BIOS supports both CHS and LBA. FreeDOS is using CHS due to the size of the CF card (~500MB). I will try forcing LBA. -I log interrupt calls out to my serial debugger on my 286. In

Re: [Freedos-devel] trying to understand execrh.asm -- calls to EXECRH cause my 286 system to lock up

Thanks again, Eric, for the previous info. I've done a bit more digging but haven't found the root cause of the issue yet. I have tried forcing LBA (using sys & sys config). I have also added a bit more debugging info on boot. I added more details to the following webpage, including a video

[Freedos-devel] stack setup in BIOS, prior to loading FreeDOS

I am working to get FreeDOS running on my 286 system. As part of this, I am trying to improve my BIOS code. As I look at the stack setup when the system initializes, I am using the following. ; org 0x xor ax, ax mov ds, ax mov

[Freedos-devel] trying to understand execrh.asm -- calls to EXECRH cause my 286 system to lock up

Hello, everyone. I am trying to better understand the EXECRH function in execrh.asm . Could someone help me understand the call being made in EXECRH of "call far[.dhp]"? To where is it calling,