[PATCH] Major bug in src/farptr.h

[william pecnik]

the patch is in attach file
to apply use "*patch src/farptr.h < farptr.patch*" from seabios directory

This will fix the problem of calling bios service int 0x13 AH=0x42 when the
drive is a ATAPI

(because Outs should use DS:SI and not ES:DI)

This bug affect all Outs() when called from real mode 16bits !

i save DS and restore it after, because Seabios use it

[Kevin O'Connor]

On Mon, Aug 05, 2024 at 04:15:00PM +0200, william pecnik wrote:
> the patch is in attach file
> to apply use "*patch src/farptr.h < farptr.patch*" from seabios directory
>
> This will fix the problem of calling bios service int 0x13 AH=0x42 when the
> drive is a ATAPI
>
> (because Outs should use DS:SI and not ES:DI)
>
> This bug affect all Outs() when called from real mode 16bits !
>
> i save DS and restore it after, because Seabios use it

Hi,

This change does not look correct.  Take a look at x86.h, where
outsb(), outsw(), and outsl() explicitly use the %es segment.

-Kevin
> diff --git a/src/farptr.h b/src/farptr.h
> index 0a4db68b..4fbe66c3 100644
> --- a/src/farptr.h
> +++ b/src/farptr.h
> @@ -161,16 +161,22 @@ static inline void insl_fl(u16 port, void *ptr_fl, u16 count) {
>      insl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count);
>  }
>  static inline void outsb_fl(u16 port, void *ptr_fl, u16 count) {
> SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
> u16 ds = GET_SEG(DS);
> SET_SEG(DS, FLATPTR_TO_SEG(ptr_fl));
> outsb(port, (u8*)FLATPTR_TO_OFFSET(ptr_fl), count);
> SET_SEG(DS, ds);
>
> }
>  static inline void outsw_fl(u16 port, void *ptr_fl, u16 count) {
> SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
> u16 ds = GET_SEG(DS);
> SET_SEG(DS, FLATPTR_TO_SEG(ptr_fl));
> outsw(port, (u16*)FLATPTR_TO_OFFSET(ptr_fl), count);
> SET_SEG(DS, ds);
>
> }
>  static inline void outsl_fl(u16 port, void *ptr_fl, u16 count) {
> SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl));
> u16 ds = GET_SEG(DS);
> SET_SEG(DS, FLATPTR_TO_SEG(ptr_fl));
> outsl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count);
> SET_SEG(DS, ds);
>
> }
>
> #else
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