[SeaBIOS] [PATCH] support T13 EDD3.0 spec

[Kevin O'Connor]

On Wed, Jan 05, 2011 at 05:18:38PM +0200, Gleb Natapov wrote:
> Some guests (such as Linux) expect BIOS to behave according to T13
> EDD3.0 spec. T13 spec is much better then Phoenix since it provides
> more information about interface and device paths. This patch adds
> support for the spec. If guest provides buffer with enough space for
> T13 EDD info return EDD according to T13 spec otherwise use Phoenix
> one.

I think Sebastian has looked at this as well.

> Signed-off-by: Gleb Natapov <gleb at redhat.com>
> diff --git a/src/disk.c b/src/disk.c
> index f7bfe9c..fb7833a 100644
> --- a/src/disk.c
> +++ b/src/disk.c
> @@ -503,6 +503,7 @@ static void
>  disk_1348(struct bregs *regs, struct drive_s *drive_g)
>  {
>      u16 size = GET_INT13DPT(regs, size);
> +    u16 t13 = size == 74;
>  
>      // Buffer is too small
>      if (size < 26) {
> @@ -553,8 +554,9 @@ disk_1348(struct bregs *regs, struct drive_s *drive_g)
>      // EDD 2.x
>  
>      int bdf;
> -    u16 iobase1;
> -    u64 device_path;
> +    u16 iobase1 = 0;
> +    u64 device_path = 0;
> +    u8 channel = 0;
>      SET_INT13DPT(regs, size, 30);
>      if (type == DTYPE_ATA || type == DTYPE_ATAPI) {
>          u16 ebda_seg = get_ebda_seg();
> @@ -573,6 +575,7 @@ disk_1348(struct bregs *regs, struct drive_s *drive_g)
>          iobase1 = GET_GLOBALFLAT(chan_gf->iobase1);
>          bdf = GET_GLOBALFLAT(chan_gf->pci_bdf);
>          device_path = slave;
> +        channel = GET_GLOBALFLAT(chan_gf->chanid);
>  
>          u16 options = 0;
>          if (type == DTYPE_ATA) {
> @@ -613,8 +616,6 @@ disk_1348(struct bregs *regs, struct drive_s *drive_g)
>          SET_INT13DPT(regs, dpte_segment, 0);
>          SET_INT13DPT(regs, dpte_offset, 0);
>          bdf = GET_GLOBAL(drive_g->cntl_id);
> -        device_path = 0;
> -        iobase1 = 0;
>      }
>  
>      if (size < 66) {
> @@ -632,17 +633,20 @@ disk_1348(struct bregs *regs, struct drive_s *drive_g)
>          SET_INT13DPT(regs, host_bus[0], 'P');
>          SET_INT13DPT(regs, host_bus[1], 'C');
>          SET_INT13DPT(regs, host_bus[2], 'I');
> -        SET_INT13DPT(regs, host_bus[3], 0);
> +        SET_INT13DPT(regs, host_bus[3], ' ');

What if we're not in t13 mode?  Should this be:
  u8 fillchar = t13 ? ' ' : 0;
  SET_INT13DPT(regs, host_bus[3], fillchar);

[...]
> +    if (13) {

That looks like a typo.

-Kevin