[PATCH 2/2] lib: fwts_acpi_tables: Force fixup on XSDT and RSDT when loading from .dat files

[Keng-Yu Lin]

On Thu, Jul 19, 2012 at 1:49 PM, Colin King <colin.king at canonical.com> wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> When loading raw ACPI tables from .dat files we have no idea where the original
> .dat tables were in memory, so this means that loading in the XSDT and RSDT is
> problematic because these contain references to the original tables in memory
> but we have no clue how these match up with the raw data.  Since fwts has to
> fake the addresses of the loaded ACPI tables these don't match those in the
> loaded XSDT and RSDT which leads to the ACPICA core getting confused.  The
> best strategy is to therefore not load the XSDT and RSDT and rely on the fwts
> table fix up stage to notice we haven't loaded the XSDT and RSDT and let this
> create these tables based on the tables we have loaded from the raw .dat data,
> leading us to having sane XSDT and RSDT that correctly reference the
> loaded ACPI tables even if they are at faked addresses.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  src/lib/src/fwts_acpi_tables.c |   21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/src/lib/src/fwts_acpi_tables.c b/src/lib/src/fwts_acpi_tables.c
> index 4db5844..f388cdd 100644
> --- a/src/lib/src/fwts_acpi_tables.c
> +++ b/src/lib/src/fwts_acpi_tables.c
> @@ -503,9 +503,24 @@ static int fwts_acpi_load_tables_from_file(fwts_framework *fw)
>                                                 name[4] = '\0';
>                                         }
>
> -                                       fwts_acpi_add_table(name, table,
> -                                               (uint64_t)fwts_fake_physical_addr(length), length,
> -                                               FWTS_ACPI_TABLE_FROM_FILE);
> +                                       if (!strncmp(name, "XSDT", 4) || !strncmp(name, "RSDT", 4)) {
> +                                               /*
> +                                                * For XSDT and RSDT we don't bother loading at this point.
> +                                                * These tables point to the other tables, however, we can't
> +                                                * figure out which table each pointer references because
> +                                                * we are loading in raw table data and we don't know where
> +                                                * these were located in the original machine.  So the best
> +                                                * way forward is to ignore these tables and instead leave
> +                                                * the fix up stage fwts_acpi_load_tables_fixup() to magically
> +                                                * create faked XSDT and RSDT entries based on the tables
> +                                                * we've loaded from file.
> +                                                */
> +                                               fwts_low_free(table);
> +                                       } else {
> +                                               fwts_acpi_add_table(name, table,
> +                                                       (uint64_t)fwts_fake_physical_addr(length), length,
> +                                                       FWTS_ACPI_TABLE_FROM_FILE);
> +                                       }
>                                 }
>                                 close(fd);
>                         } else
> --
> 1.7.10.4
>
Acked-by: Keng-Yu Lin <kengyu at canonical.com>