Re: [PATCH] applesmc: add sysfs file to report OSK

From: Alexander Graf
Date: Mon Dec 10 2012 - 11:42:56 EST




On 10.12.2012, at 15:51, "Gabriel L. Somlo" <somlo@xxxxxxx> wrote:

> The AppleSMC contains two char[32] keys, OSK0 and OSK1, which are not
> reported in the key count and index by default. These keys are used by
> the OS X boot sequence, and normally don't matter when running Linux.
>
> This patch creates a sysfs entry which reports the value of these keys
> as an ASCII string, to help emulators (such as QEMU) load OS X when
> running on genuine Apple hardware.
>
> Signed-off-by: Gabriel L. Somlo <somlo@xxxxxxx>

Acked-by: Alexander Graf <agraf@xxxxxxx>

Alex

> ---
>
> For extra context: To boot OS X as a guest, QEMU must (among others)
> emulate the AppleSMC. To boot successfully, OS X insists on querying
> the (emulated) SMC for the value of OSK0 and OSK1. Currently, these
> values must be supplied on the QEMU command line as
>
> -device applesmc,osk="...concatenated values of OSK0 and OSK1..."
>
> With the availability of /sys/devices/platform/applesmc.768/osk, the
> emulated QEMU AppleSMC could acquire this string directly from the
> (Apple-manufactured) host machine.
>
> Thanks,
> Gabriel
>
> drivers/hwmon/applesmc.c | 18 ++++++++++++++++++
> 1 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
> index b41baff..0c7cc71 100644
> --- a/drivers/hwmon/applesmc.c
> +++ b/drivers/hwmon/applesmc.c
> @@ -1013,6 +1013,23 @@ static ssize_t applesmc_key_at_index_store(struct device *dev,
> return count;
> }
>
> +static ssize_t applesmc_osk_show(struct device *dev,
> + struct device_attribute *attr, char *sysfsbuf)
> +{
> + int fail;
> +
> + mutex_lock(&smcreg.mutex);
> + fail = read_smc(APPLESMC_READ_CMD, "OSK0", sysfsbuf, 32) ||
> + read_smc(APPLESMC_READ_CMD, "OSK1", sysfsbuf + 32, 32);
> + mutex_unlock(&smcreg.mutex);
> + if (fail)
> + return -1;
> +
> + sysfsbuf[64] = '\n';
> + sysfsbuf[65] = '\0';
> + return 65;
> +}
> +
> static struct led_classdev applesmc_backlight = {
> .name = "smc::kbd_backlight",
> .default_trigger = "nand-disk",
> @@ -1027,6 +1044,7 @@ static struct applesmc_node_group info_group[] = {
> { "key_at_index_type", applesmc_key_at_index_type_show },
> { "key_at_index_data_length", applesmc_key_at_index_data_length_show },
> { "key_at_index_data", applesmc_key_at_index_read_show },
> + { "osk", applesmc_osk_show },
> { }
> };
>
> --
> 1.7.7.6
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/