OSDev.org

Hi,

I have a little problem, and need help to solve it

I have a floppy driver that can read sectors from the disk. it use DMA
i have a Vesa driver that can switch to graphic mode/returns to text mode ; it use vesa 2.0 , and switch between real& protected mode to switch the graphic mode

the floppy driver works when i'm in text mode
when i'm in graphic mode, the floppy driver seem to block (maybe problem with dma interrupt ?)
when i'm in graphic mode, then i go back to text mode, the floppy driver works

this not work :
SetMode mode1024x768x24
ReadFile
...do something ://this dont' seem to be reached,

but this works:
SetMode mode1024x768x24
ExitMode
ReadFile
SetMode mode1024x768x24
... do something ;//this seem to be executed correctly


do you know if there's is similar known problems and how i can solve it?

I am ill. What medication should I take and for how long?

Are you sure it's the disk access that's failing rather than graphics mode preventing whatever feedback to reach the user - printing text in graphics modes doesn't necessarily need to work.

as i said,

when i'm in graphic mode, it seem that the os block somewhere when i try to read a file (or a sector in the disk). not when i'm in text mode.

basicaly, i have to go back to text mode, before to read a file, then return to the graphic mode ;

when i read the file before entering in graphic mode, it works correctly and continue to the next step (switch to graphic mode, display some graphics and mouse cursor)
when i enter to the graphic mode, before to read the file, it block (normaly it should display some graphics to the screen, but it does'nt, the screen stay black)
when i enter to the graphic mode, then go back to text mode, then read the file, then return to graphic mode, it works (display some graphics, mouse working, etc...)

i can not find a logic cause of that :/

Solved

it seem that when i output something to the textmode console, while i'm in graphic mode, the sytem crashes. (idont know why)

I solved the problem by redirecting the output to another function that display the messages in the graphic buffer instead of the text mode memory.