Re: [PATCH] term/ns8250-spcr: Add one more 16550 debug type.

[Glenn Washburn]

On Fri, 7 Jun 2024 23:57:14 +0200
Udo Steinberg <udo@hypervisor.org> wrote:

> Hi all,
> 
> below is a patch for picking up the correct UART address from the ACPI SPCR
> table on modern AWS bare-metal instances.
> 
> CC: Benjamin and Glenn for review.
> 
> Cheers,
> Udo

LGTM for the changes itself. I don't think you used git to send the
patch, but this is small enough that perhaps Daniel won't have an issue
applying it.

Reviewed-by: Glenn Washburn <development@efficientek.com>

Glenn Washburn

> 
> --
> 
> From ddb2b0f0da4f5f6be13a70d5a8d7dff6f90e2208 Mon Sep 17 00:00:00 2001
> From: Udo Steinberg <udo@hypervisor.org>
> Date: Fri, 7 Jun 2024 23:44:43 +0200
> Subject: [PATCH] term/ns8250-spcr: Add one more 16550 debug type.
> 
> Type 0x1 was introduced with the ACPI DBGP table and type 0x12 was introduced
> with the ACPI DBG2 table. Type 0x12 is used by the ACPI SPCR table on recent
> AWS bare-metal instances (c6i/c7i). Also give each debug type a proper name.
> 
> Signed-off-by: Udo Steinberg <udo@hypervisor.org>
> ---
>  grub-core/term/ns8250-spcr.c | 3 ++-
>  include/grub/acpi.h          | 5 +++--
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/grub-core/term/ns8250-spcr.c b/grub-core/term/ns8250-spcr.c
> index d52b52c26..4efaaf768 100644
> --- a/grub-core/term/ns8250-spcr.c
> +++ b/grub-core/term/ns8250-spcr.c
> @@ -38,7 +38,8 @@ grub_ns8250_spcr_init (void)
>      grub_dprintf ("serial", "SPCR table revision %d < 2, continuing 
> anyway\n",
>                 (int) spcr->hdr.revision);
>    if (spcr->intf_type != GRUB_ACPI_SPCR_INTF_TYPE_16550 &&
> -      spcr->intf_type != GRUB_ACPI_SPCR_INTF_TYPE_16550X)
> +      spcr->intf_type != GRUB_ACPI_SPCR_INTF_TYPE_16550_DBGP &&
> +      spcr->intf_type != GRUB_ACPI_SPCR_INTF_TYPE_16550_DBG2)
>      return NULL;
>    /* For now, we only support byte accesses. */
>    if (spcr->base_addr.access_size != GRUB_ACPI_GENADDR_SIZE_BYTE &&
> diff --git a/include/grub/acpi.h b/include/grub/acpi.h
> index f2862da74..1046f22d7 100644
> --- a/include/grub/acpi.h
> +++ b/include/grub/acpi.h
> @@ -200,8 +200,9 @@ struct grub_acpi_genaddr {
>  struct grub_acpi_spcr {
>    struct grub_acpi_table_header hdr;
>    grub_uint8_t intf_type;
> -#define GRUB_ACPI_SPCR_INTF_TYPE_16550  0x00
> -#define GRUB_ACPI_SPCR_INTF_TYPE_16550X 0x01
> +#define GRUB_ACPI_SPCR_INTF_TYPE_16550      0x00
> +#define GRUB_ACPI_SPCR_INTF_TYPE_16550_DBGP 0x01
> +#define GRUB_ACPI_SPCR_INTF_TYPE_16550_DBG2 0x12
>    grub_uint8_t reserved_0[3];
>    struct grub_acpi_genaddr base_addr;
>    grub_uint8_t interrupt_type;