Re: [PATCH 7/8] Provide a Console Terminal Block in the HWRPB.

[Richard Henderson <richard.henderson@linaro.org>]

On 6/2/21 8:53 PM, Jason Thorpe wrote:
> +  hwrpb.hwrpb.ctbt_offset = offsetof(struct hwrpb_combine, ctb);
> +  hwrpb.hwrpb.ctb_size = sizeof(hwrpb.ctb);
> +  if (have_vga && !CONFIG_NOGRAPHICS(config))
> +    {
> +      hwrpb.ctb.term_type = CTB_GRAPHICS;
> +      hwrpb.ctb.turboslot = (CTB_TURBOSLOT_TYPE_PCI << 16) |
> +			    (pci_vga_bus << 8) | pci_vga_dev;
> +    }
> +  else
> +    {
> +      hwrpb.ctb.term_type = CTB_PRINTERPORT;
> +    }

I'm concerned that you're initializing only 1 or 2 slots of 34.

It would seem that at a bare minimum the struct should be zeroed, and the 
device-independent header (4 slots) should be set.

I notice you're setting term_type (offset 56) and not type (offset 0), which is 
where my documentation says that CTB_GRAPHICS goes (Console Interface 
Architecture 2.3.8.2 Console Terminal Block Table).

I'm also confused that this

> + * Format of the Console Terminal Block Type 4 `turboslot' field:

says "type 4", but you're actually using type 3 (GRAPHICS) above.

But I do see that what you're filling in is exactly what netbsd examines -- no 
header checks, no size checks, or anything.  And that openbsd has an exact copy 
of that code.


r~