Re: [flashrom] [PATCH 5/7] warn if SMM BIOS Write Protection is detected in BIOS_CNTL

[Stefan Reinauer]

On 5/23/11 4:23 PM, Stefan Tauner wrote:
> Signed-off-by: Stefan Tauner
>
> chipset_enable.c |   12 +++++++++++-
>   1 files changed, 11 insertions(+), 1 deletions(-)
>
> diff --git a/chipset_enable.c b/chipset_enable.c
> index 83b49ad..339c6bb 100644
> --- a/chipset_enable.c
> +++ b/chipset_enable.c
> @@ -264,8 +264,18 @@ static int enable_flash_ich(struct pci_dev *dev, const char *name,
>    	     (old&  (1<<  0)) ? "en" : "dis");
>    msg_pdbg("BIOS_CNTL is 0x%x\n", old);
> new = old | 1;
> /*
> * Quote from the 6 Series datasheet:
> * "5: SMM BIOS Write Protect Disable (SMM_BWP)
> * 1 = BIOS region SMM protection is enabled.
> * The BIOS Region is not writable unless all processors are in SMM."
> * In earlier chipsets this bit is reserved. */
> if (old&  (5<<  1)) {
> msg_pinfo("WARNING: BIOS region SMM protection is enabled!\n");
> return -1;

You might still be successful doing the write, in case the SMM handler 
does not enforce the protection, so maybe you should just print a 
warning but not return here?
> }
>
> new = old | 1;
> if (new == old)
> return 0;