Folks, May I please get some feedback on this?
Thanks
On Tue, Sep 22, 2015 at 02:01:03PM -0700, Arthur Mesh wrote:
> Starting with d9a0c9413e81d3c0affc6383693bdd28dc863a5c, GRUB unconditionally
> disables watchdog on EFI platforms. This opens up a window (starting at GRUB's
> grub_efi_init(), until OS re-enables it) when EFI system operates w/o
> watchdog.
> If an EFI system gets stuck in that window, the chipset will never reset the
> system.
>
> Create a command line interface to enable/disable watchdog:
> efi-watchdog (enable|disable) <code> <timeout>
> ---
> docs/grub.texi | 11 ++++++++
> grub-core/kern/efi/init.c | 68
> +++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 79 insertions(+)
>
> diff --git a/docs/grub.texi b/docs/grub.texi
> index b9f41a7..507e1c6 100644
> --- a/docs/grub.texi
> +++ b/docs/grub.texi
> @@ -3784,6 +3784,7 @@ you forget a command, you can run the command
> @command{help}
> * distrust:: Remove a pubkey from trusted keys
> * drivemap:: Map a drive to another
> * echo:: Display a line of text
> +* efi-watchdog:: Manipulate EFI watchdog
> * eval:: Evaluate agruments as GRUB commands
> * export:: Export an environment variable
> * false:: Do nothing, unsuccessfully
> @@ -4192,6 +4193,16 @@ When interpreting backslash escapes, backslash
> followed by any other
> character will print that character.
> @end deffn
>
> +@node efi-watchdog
> +@subsection efi-watchdog
> +
> +@deffn Command efi-watchdog enable|disable <code> <timeout>
> +Enable or disable the system's watchdog timer. Only available in EFI targeted
> +GRUB.
> +The <code> is logged upon watchdog timeout event. The UEFI BIOS reserves
> codes
> +0x0000 to 0xFFFF.
> +The <timeout> represents number of seconds to set the watchdog timeout to.
> +@end deffn
>
> @node eval
> @subsection eval
> diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
> index e9c85de..e3d8288 100644
> --- a/grub-core/kern/efi/init.c
> +++ b/grub-core/kern/efi/init.c
> @@ -25,9 +25,73 @@
> #include <grub/env.h>
> #include <grub/mm.h>
> #include <grub/kernel.h>
> +#include <grub/extcmd.h>
> +#include <grub/command.h>
>
> grub_addr_t grub_modbase;
>
> +static grub_command_t cmd_list;
> +
> +static grub_err_t
> +grub_cmd_efi_watchdog (grub_command_t cmd __attribute__ ((unused)),
> + int argc, char **args)
> +{
> + long input;
> + grub_efi_status_t status;
> + grub_efi_uintn_t timeout;
> + grub_efi_uint64_t code;
> +
> + if (argc < 1)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("usage: efi-watchdog (enable|disable) <code> <timeout>"));
> +
> + if (grub_strcasecmp (args[0], "enable") == 0) {
> +
> + if (argc != 3)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("usage: efi-watchdog enable <code>
> <timeout>"));
> +
> + input = grub_strtol (args[1], 0, 0);
> +
> + if (input >= 0) {
> + code = input;
> + } else {
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("<code> must be non-negative"));
> + }
> +
> + input = grub_strtol (args[2], 0, 0);
> +
> + if (input >= 0) {
> + timeout = (grub_efi_uintn_t) input;
> + } else {
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("<timeout> must be non-negative"));
> + }
> +
> + } else if (grub_strcasecmp (args[0], "disable") == 0) {
> +
> + if (argc != 1)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("usage: efi-watchdog disable"));
> + timeout = 0;
> + code = 0;
> +
> + } else {
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + N_("usage: efi-watchdog (enable|disable) <code> <timeout>"));
> + }
> +
> + status = efi_call_4
> (grub_efi_system_table->boot_services->set_watchdog_timer,
> + timeout, code, sizeof(L"GRUB"), L"GRUB");
> +
> + if (status != GRUB_EFI_SUCCESS)
> + return grub_error (GRUB_ERR_BUG,
> + N_("Unexpected UEFI SetWatchdogTimer() error"));
> + else
> + return GRUB_ERR_NONE;
> +}
> +
> void
> grub_efi_init (void)
> {
> @@ -43,6 +107,9 @@ grub_efi_init (void)
> 0, 0, 0, NULL);
>
> grub_efidisk_init ();
> +
> + cmd_list = grub_register_command ("efi-watchdog", grub_cmd_efi_watchdog, 0,
> + N_("Enable/Disable system's watchdog
> timer."));
> }
>
> void (*grub_efi_net_config) (grub_efi_handle_t hnd,
> @@ -77,4 +144,5 @@ grub_efi_fini (void)
> {
> grub_efidisk_fini ();
> grub_console_fini ();
> + grub_unregister_command (cmd_list);
> }
> --
> 1.7.9.5
>
>
> --
> Arthur Mesh <am...@juniper.net>
> Juniper Networks
> +1 408 936-4968
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2
>
> iQGcBAABCAAGBQJWAcGPAAoJEAi6IWerhQY4bQ8L/iAKVJCQdouysH/vytGcgzuY
> Vewzpamm+ey0VXwve5nCgFaPhtXFppwt25obolfNPQyXnm5p7XX8fe8y4q34ZQ2S
> 6LiGHSXHFk9YfJOimc9Qdm+FcdTsuTLfG7nx/nUGfVP5tMPseC/26j7imRHP83lb
> lDIKvDErhVTQPFHlnQhNix3LM+EPAfhlM9IvbwQ38FNjg4dPuSb9PLEAu4SG2TAt
> QmLWJ+M99LXOzRoppN+bsmsO7mlb+v8sd//UUK+PpuA6dN2RSD6K+pe5+y6a4Msx
> SKvn6dsdALR7BlLgnars+7uX6/TF5gEh/8a1MF9z+Y2HuUVMQQJwzDXners297Qg
> hnMn32lhR7dZWpL2IRMhyN6gdunI+nUFBVXTwmJlU78wMVVLIM1kgsfdi4Rn/diU
> svdAX526gT3H6VUsFhgMuoqJ1nWmIWwfd/99Jf3Md746ZgB/BWCCs+MZzpkdjYz2
> wGPgi21eK6wGHJPXp8ho+Up6W6yoB+NpEEH1xlnHXg==
> =Ecr5
> -----END PGP SIGNATURE-----
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel
--
Arthur Mesh <am...@juniper.net>
Juniper Networks
+1 408 936-4968
signature.asc
Description: PGP signature
_______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
