ACK: [PATCH] lib: fwts_acpi_tables: update RSDP checksum on fixed-up RSDP (LP: #1287852)

[IvanHu]

On 03/05/2014 02:56 AM, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> When loading the RSDP from a file sometimes the XSDT and/or RSDT
> have been updated (fixed up) which requires clearing the old
> checksums and re-calculating them for the updated RSDP. Currently
> this is not occurring, causing fwts checksum tests to fail on the
> RSDP on fixed up tables loaded from file. This patch fixes this.
>
> 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 cccf9ba..9932da6 100644
> --- a/src/lib/src/fwts_acpi_tables.c
> +++ b/src/lib/src/fwts_acpi_tables.c
> @@ -634,6 +634,7 @@ static int fwts_acpi_load_tables_fixup(fwts_framework *fw)
>   	fwts_acpi_table_fadt *fadt = NULL;
>   	fwts_acpi_table_facs *facs = NULL;
>   	uint64_t rsdt_fake_addr = 0, xsdt_fake_addr = 0;
> +	bool redo_rsdp_checksum = false;
>
>   	/* Fetch the OEM Table ID */
>   	if (fwts_acpi_find_table(fw, "FACP", 0, &table) != FWTS_OK) {
> @@ -784,15 +785,29 @@ static int fwts_acpi_load_tables_fixup(fwts_framework *fw)
>   		rsdp->reserved[2] = 0;
>
>   		rsdp->checksum = 256 - fwts_checksum((uint8_t*)rsdp, 20);
> -		rsdp->extended_checksum = 256 - fwts_checksum((uint8_t*)rsdp, sizeof(fwts_acpi_table_rsdp));
> +		rsdp->extended_checksum = 256 - fwts_checksum((uint8_t*)rsdp, rsdp->length);
>
>   		fwts_acpi_add_table("RSDP", rsdp, (uint64_t)fwts_fake_physical_addr(size),
>   			sizeof(fwts_acpi_table_rsdp), FWTS_ACPI_TABLE_FROM_FIXUP);
>   	}
>
>   	/* Now we have all the tables, final fix up is required */
> -	rsdp->rsdt_address = rsdt_fake_addr;
> -	rsdp->xsdt_address = xsdt_fake_addr;
> +	if (rsdp->rsdt_address != rsdt_fake_addr) {
> +		rsdp->rsdt_address = rsdt_fake_addr;
> +		redo_rsdp_checksum = true;
> +	}
> +	if ((rsdp->revision > 0) && (rsdp->length >= 36) &&
> +	    (rsdp->xsdt_address != xsdt_fake_addr)) {
> +		rsdp->xsdt_address = xsdt_fake_addr;
> +		redo_rsdp_checksum = true;
> +	}
> +	/* And update checksum if we've updated the rsdp */
> +	if (redo_rsdp_checksum) {
> +		rsdp->checksum = 0;	/* Clear old checksum */
> +		rsdp->checksum = 256 - fwts_checksum((uint8_t*)rsdp, 20);
> +		rsdp->extended_checksum = 0;	/* Clear old checksum */
> +		rsdp->extended_checksum = 256 - fwts_checksum((uint8_t*)rsdp, rsdp->length);
> +	}
>
>   	return FWTS_OK;
>   }
>


Acked-by: Ivan Hu <ivan.hu at canonical.com>