[SeaBIOS] Re: [PATCH] acpi: add xsdt support

[Igor Mammedov]

On Fri, 27 Mar 2020 09:24:10 +0100
Gerd Hoffmann  wrote:
> In case a xsdt table is present (and located below 4G)
> prefer it over rsdt.

not related to this patch, but in connection to supporting HW reduced
profile, check places that use FADT.
i.e.
 * check for newer FADT revision
 * skip pm timer init if hw reduced flag is set
 * not sure what to do but there isn't FACS in hw reduced
   so we might need something else in find_resume_vector()
> Signed-off-by: Gerd Hoffmann
>
> src/std/acpi.h      | 11 +++++++++++
>  src/fw/biostables.c | 40 ++++++++++++++++++++++++++++++----------
>  2 files changed, 41 insertions(+), 10 deletions(-)
>
> diff --git a/src/std/acpi.h b/src/std/acpi.h
> index c01fa7be827c..81c22757f50e 100644
> --- a/src/std/acpi.h
> +++ b/src/std/acpi.h
> @@ -132,6 +132,17 @@ struct rsdt_descriptor_rev1
>      /* ACPI tables */
>  } PACKED;
>
> +/*
> ACPI 2.0 eXtended System Description Table (XSDT)
> */
>
> +#define XSDT_SIGNATURE 0x54445358 // XSDT
> +struct xsdt_descriptor_rev2
> +{
> ACPI_TABLE_HEADER_DEF       /* ACPI common table header */
> u64 table_offset_entry[0];  /* Array of pointers to other */
> /* ACPI tables */
>
> +} PACKED;
>
> /*
> ACPI 1.0 Firmware ACPI Control Structure (FACS)
>
> */
> diff --git a/src/fw/biostables.c b/src/fw/biostables.c
> index fe8626efc05d..0d4fdb9c22e8 100644
> --- a/src/fw/biostables.c
> +++ b/src/fw/biostables.c
> @@ -141,18 +141,38 @@ find_acpi_table(u32 signature)
>      if (!RsdpAddr || RsdpAddr->signature != RSDP_SIGNATURE)
>          return NULL;
>      struct rsdt_descriptor_rev1 *rsdt = (void*)RsdpAddr->rsdt_physical_address;
> struct xsdt_descriptor_rev2 *xsdt =
>    RsdpAddr->xsdt_physical_address >= 0x100000000
>    ? NULL : (void*)(u32)(RsdpAddr->xsdt_physical_address);
> dprintf(4, "rsdt=%p\n", rsdt);
> if (!rsdt || rsdt->signature != RSDT_SIGNATURE)
>    return NULL;
> void *end = (void*)rsdt + rsdt->length;
> int i;
> for (i=0; (void*)&rsdt->table_offset_entry[i] < end; i++) {
>    struct acpi_table_header *tbl = (void*)rsdt->table_offset_entry[i];
>    if (!tbl || tbl->signature != signature)
>        continue;
>    dprintf(4, "table(%x)=%p\n", signature, tbl);
>    return tbl;
> dprintf(4, "xsdt=%p\n", xsdt);
> if (xsdt && xsdt->signature == XSDT_SIGNATURE) {
>    void *end = (void*)xsdt + xsdt->length;
>    int i;
>    for (i=0; (void*)&xsdt->table_offset_entry[i] < end; i++) {
>        if (xsdt->table_offset_entry[i] >= 0x100000000)
>            continue; /* above 4G */

can it print a error in such cases, so that user could see that there are unsupported tables
in used machine?
>        struct acpi_table_header *tbl = (void*)(u32)xsdt->table_offset_entry[i];
>        if (!tbl || tbl->signature != signature)
>            continue;
>        dprintf(1, "table(%x)=%p (via xsdt)\n", signature, tbl);
>        return tbl;
>    }
> }
> if (rsdt && rsdt->signature == RSDT_SIGNATURE) {
>    void *end = (void*)rsdt + rsdt->length;
>    int i;
>    for (i=0; (void*)&rsdt->table_offset_entry[i] < end; i++) {
>        struct acpi_table_header *tbl = (void*)rsdt->table_offset_entry[i];
>        if (!tbl || tbl->signature != signature)
>            continue;
>        dprintf(1, "table(%x)=%p (via rsdt)\n", signature, tbl);
>        return tbl;
>    }
> }
> dprintf(4, "no table %x found\n", signature);
>    return NULL;
>
> }