In kernel 5.16 special ioctls were introduced to get/set RTC parameters.
Add option to get/set parameters into busybox version of hwclock.
Implementation is similar to the one already used in linux-utils hwclock
tool.
Example of parameter get use:
$ hwclock -g 2
The RTC parameter 0x2 is set to 0x2.
$ hwclock --param-get bsm
The RTC parameter 0x2 is set to 0x2.
Example of parameter set use:
$ hwclock -p 2=1
The RTC parameter 0x2 will be set to 0x1.
$ hwclock -p bsm=2
The RTC parameter 0x2 will be set to 0x2.
Signed-off-by: Andrej Picej <andrej.pi...@norik.com>
---
include/rtc_.h | 23 +++++++++
util-linux/hwclock.c | 119 +++++++++++++++++++++++++++++++++++++++++--
2 files changed, 137 insertions(+), 5 deletions(-)
diff --git a/include/rtc_.h b/include/rtc_.h
index 24ff536..4b8d9fc 100644
--- a/include/rtc_.h
+++ b/include/rtc_.h
@@ -22,6 +22,11 @@ int rtc_xopen(const char **default_rtc, int flags) FAST_FUNC;
void rtc_read_tm(struct tm *ptm, int fd) FAST_FUNC;
time_t rtc_tm2time(struct tm *ptm, int utc) FAST_FUNC;
+struct hwclock_param {
+ int id;
+ const char *name;
+ const char *help;
+};
/*
* Everything below this point has been copied from linux/rtc.h
@@ -46,6 +51,17 @@ struct linux_rtc_wkalrm {
struct linux_rtc_time time; /* time the alarm is set to */
};
+struct rtc_param {
+ __u64 param;
+ union {
+ __u64 uvalue;
+ __s64 svalue;
+ __u64 ptr;
+ };
+ __u32 index;
+ __u32 __pad;
+};
+
/*
* ioctl calls that are permitted to the /dev/rtc interface, if
* any of the RTC drivers are enabled.
@@ -71,12 +87,19 @@ struct linux_rtc_wkalrm {
#define RTC_WKALM_SET _IOW('p', 0x0f, struct linux_rtc_wkalrm)/* Set wakeup
alarm*/
#define RTC_WKALM_RD _IOR('p', 0x10, struct linux_rtc_wkalrm)/* Get wakeup
alarm*/
+#define RTC_PARAM_GET _IOW('p', 0x13, struct rtc_param) /* Get parameter */
+#define RTC_PARAM_SET _IOW('p', 0x14, struct rtc_param) /* Set parameter */
+
/* interrupt flags */
#define RTC_IRQF 0x80 /* any of the following is active */
#define RTC_PF 0x40
#define RTC_AF 0x20
#define RTC_UF 0x10
+# define RTC_PARAM_FEATURES 0
+# define RTC_PARAM_CORRECTION 1
+# define RTC_PARAM_BACKUP_SWITCH_MODE 2
+
POP_SAVED_FUNCTION_VISIBILITY
#endif
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index 723b095..0a49671 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -48,6 +48,19 @@
# define LIBC_IS_MUSL 0
#endif
+static const struct hwclock_param hwclock_params[] =
+{
+ { RTC_PARAM_FEATURES, "features", "supported features" },
+ { RTC_PARAM_CORRECTION, "correction", "time correction" },
+ { RTC_PARAM_BACKUP_SWITCH_MODE, "bsm", "backup switch mode" },
+ { }
+};
+
+const struct hwclock_param *get_hwclock_params(void)
+{
+ return hwclock_params;
+}
+
/* diff code is disabled: it's not sys/hw clock diff, it's some useless
* "time between hwclock was started and we saw CMOS tick" quantity.
@@ -320,6 +333,89 @@ static void from_sys_clock(const char **pp_rtcname, int
utc)
close(rtc);
}
+static int resolve_rtc_param_alias(const char *alias, __u64 *value)
+{
+ const struct hwclock_param *param = &hwclock_params[0];
+
+ while (param->name) {
+ if (!strcmp(alias, param->name)) {
+ *value = param->id;
+ return 0;
+ }
+ param++;
+ }
+
+ return 1;
+}
+
+static void get_rtc_param(const char **pp_rtcname, const char *rtc_param)
+{
+ int rtc;
+ struct rtc_param param = { .param = 0 };
+
+ if (resolve_rtc_param_alias(rtc_param, ¶m.param) != 0) {
+ param.param = bb_strtoull(rtc_param, NULL, 0);
+ if (errno)
+ bb_error_msg_and_die("could not convert parameter name:
'%s' to number", rtc_param);
+ }
+
+ rtc = rtc_xopen(pp_rtcname, O_RDONLY);
+
+ xioctl(rtc, RTC_PARAM_GET, ¶m);
+
+ printf("The RTC parameter 0x%jx is set to 0x%jx.\n",
+ (uintmax_t) param.param, (uintmax_t) param.uvalue);
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(rtc);
+}
+
+static void set_rtc_param(const char **pp_rtcname, const char *rtc_param)
+{
+ int rtc;
+ int ret = 1;
+ struct rtc_param param = { .param = 0 };
+ char *tok, *opt = xstrdup(rtc_param);
+
+ /* handle param name */
+ tok = strtok(opt, "=");
+ if (resolve_rtc_param_alias(tok, ¶m.param) != 0) {
+ param.param = bb_strtoull(tok, NULL, 0);
+ if (errno) {
+ bb_error_msg("could not convert parameter name: '%s' to
number", tok);
+ goto done;
+ }
+ }
+
+ /* handle param value */
+ tok = strtok(NULL, "=");
+ if (!tok) {
+ bb_error_msg("expected <param>=<value>");
+ goto done;
+ }
+ param.uvalue = bb_strtoull(tok, NULL, 0);
+ if (errno) {
+ bb_error_msg("could not convert parameter value to number");
+ goto done;
+ }
+
+ rtc = rtc_xopen(pp_rtcname, O_WRONLY);
+
+ printf("The RTC parameter 0x%jx will be set to 0x%jx.\n",
+ (uintmax_t) param.param, (uintmax_t) param.uvalue);
+
+ xioctl(rtc, RTC_PARAM_SET, ¶m);
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(rtc);
+
+ ret = 0;
+done:
+ free(opt);
+ if (ret)
+ bb_error_msg_and_die("error: %d", ret);
+}
+
// hwclock from util-linux 2.36.1
// hwclock [function] [option...]
//Functions:
@@ -346,10 +442,10 @@ static void from_sys_clock(const char **pp_rtcname, int
utc)
//usage:#define hwclock_trivial_usage
//usage: IF_LONG_OPTS(
-//usage: "[-swul] [--systz] [-f DEV]"
+//usage: "[-swul] [--systz] [--param-get PARAM] [--param-set PARAM=VAL]
[-f DEV]"
//usage: )
//usage: IF_NOT_LONG_OPTS(
-//usage: "[-swult] [-f DEV]"
+//usage: "[-swult] [-g PARAM] [-p PARAM=VAL] [-f DEV]"
//usage: )
//usage:#define hwclock_full_usage "\n\n"
//usage: "Show or set hardware clock (RTC)\n"
@@ -360,6 +456,8 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
//usage: IF_LONG_OPTS(
//usage: "\n --systz Set in-kernel timezone, correct system time"
//usage: "\n if RTC is kept in local time"
+//usage: "\n --param-get PARAM Get RTC parameter"
+//usage: "\n --param-set PARAM=VAL Set RTC parameter"
//usage: )
//usage: "\n -f DEV Use specified device (e.g. /dev/rtc2)"
//usage: "\n -u Assume RTC is kept in UTC"
@@ -375,11 +473,14 @@ static void from_sys_clock(const char **pp_rtcname, int
utc)
#define HWCLOCK_OPT_SYSTOHC 0x10
#define HWCLOCK_OPT_SYSTZ 0x20
#define HWCLOCK_OPT_RTCFILE 0x40
+#define HWCLOCK_OPT_PARAM_GET 0x80
+#define HWCLOCK_OPT_PARAM_SET 0x100
int hwclock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hwclock_main(int argc UNUSED_PARAM, char **argv)
{
const char *rtcname = NULL;
+ const char *param = NULL;
unsigned opt;
int utc;
#if ENABLE_LONG_OPTS
@@ -391,14 +492,18 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
"systohc\0" No_argument "w"
"systz\0" No_argument "t" /* short opt is non-standard */
"rtc\0" Required_argument "f"
+ "param-get\0" Required_argument "g" /* short opt is
non-standard */
+ "param-set\0" Required_argument "p" /* short opt is
non-standard */
;
#endif
opt = getopt32long(argv,
- "^""lurswtf:v" /* -v is accepted and ignored */
+ "^""lurswtf:g:p:v" /* -v is accepted and ignored */
"\0"
- "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l",
+
"r--wstgp:w--rstgp:s--wrtgp:t--rswgp:g--rswtp:p--rswtg:l--u:u--l",
hwclock_longopts,
- &rtcname
+ &rtcname,
+ ¶m,
+ ¶m
);
/* If -u or -l wasn't given, check if we are using utc */
@@ -413,6 +518,10 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
from_sys_clock(&rtcname, utc);
else if (opt & HWCLOCK_OPT_SYSTZ)
set_kernel_timezone_and_clock(utc, NULL);
+ else if (opt & HWCLOCK_OPT_PARAM_GET)
+ get_rtc_param(&rtcname, param);
+ else if (opt & HWCLOCK_OPT_PARAM_SET)
+ set_rtc_param(&rtcname, param);
else
/* default HWCLOCK_OPT_SHOW */
show_clock(&rtcname, utc);
--
2.25.1
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