✨ Expose VEXos' time and date functions (#127)

* Expose VEXos' get time and date functions * wip: add clock_gettime impl * wip: fix errors with clock_gettime impl * wip: add _gettimeofday impl * Push code to build test for time implementation * Add integer timestamp to the generated timestamp info * Fix compile errors * Fix compile errors 2 * Change _PROS_COMPILE_TIMESTAMP_INT to be an actual integer * Test linking against _pros_ld_timestamp.o variables * Test linking against _pros_ld_timestamp.o variables 2 * Test linking against _pros_ld_timestamp.o variables 3 * Test linking against _pros_ld_timestamp.o variables 4 * Convert _PROS_COMPILE_TIMESTAMP_INT back into a string * Try using HOT_TABLE rather than the timestamp directly * Make _PROS_COMPILESTAMP_INT a weak symbol * Fix compiler error * Attempt to use functions to subvert linking issues * Try switching _PROS_COMPILE_TIMESTAMP_INT to an integer again * Revert back to hacky callback solution * Fix compile error * Fix compile error 2 * Fix compile error 3 * Fix compile error 4 * Fix? * Fix microsecond calculation * Account for timezones when generating _PROS_COMPILE_TIMESTAMP_INT * Fix formatting and accidental changes * Commit for applying template * Fix compilation errors and begin implementing clock_settime() * Update firmware * Update common.mk to allow POSIX functions in time.h * Add CLOCK_MONOTONIC to clock_gettime() * Add comment * Fix version Co-authored-by: Alex Brooke <[email protected]> Co-authored-by: WillXuCodes <[email protected]> Co-authored-by: Richard Stump <[email protected]>
purduesigbots · Oct 18, 2022 · a1e0d24 · a1e0d24
1 parent 2cf5fb2
commit a1e0d24
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Showing 7 changed files with 159 additions and 4 deletions.
diff --git a/common.mk b/common.mk
@@ -2,7 +2,7 @@ ARCHTUPLE=arm-none-eabi-
 DEVICE=VEX EDR V5
 
 MFLAGS=-mcpu=cortex-a9 -mfpu=neon-fp16 -mfloat-abi=softfp -Os -g
-CPPFLAGS=-D_POSIX_THREADS -D_UNIX98_THREAD_MUTEX_ATTRIBUTES
+CPPFLAGS=-D_POSIX_THREADS -D_UNIX98_THREAD_MUTEX_ATTRIBUTES -D_POSIX_TIMERS -D_POSIX_MONOTONIC_CLOCK
 GCCFLAGS=-ffunction-sections -fdata-sections -fdiagnostics-color -funwind-tables
 
 WARNFLAGS+=-Wno-psabi
@@ -227,7 +227,7 @@ $(COLD_BIN): $(COLD_ELF)
 $(COLD_ELF): $(COLD_LIBRARIES)
 	$(VV)mkdir -p $(dir $@)
 	$(call test_output_2,Creating cold package with $(ARCHIVE_TEXT_LIST) ,$(LD) $(LDFLAGS) $(call wlprefix,--gc-keep-exported --whole-archive $^ -lstdc++ --no-whole-archive) $(call wlprefix,-T$(FWDIR)/v5.ld $(LNK_FLAGS) -o $@),$(OK_STRING))
-	$(call test_output_2,Stripping cold package ,$(OBJCOPY) --strip-symbol=install_hot_table --strip-symbol=__libc_init_array --strip-symbol=_PROS_COMPILE_DIRECTORY --strip-symbol=_PROS_COMPILE_TIMESTAMP $@ $@, $(DONE_STRING))
+	$(call test_output_2,Stripping cold package ,$(OBJCOPY) --strip-symbol=install_hot_table --strip-symbol=__libc_init_array --strip-symbol=_PROS_COMPILE_DIRECTORY --strip-symbol=_PROS_COMPILE_TIMESTAMP --strip-symbol=_PROS_COMPILE_TIMESTAMP_INT $@ $@, $(DONE_STRING))
 	@echo Section sizes:
 	-$(VV)$(SIZETOOL) $(SIZEFLAGS) $@ $(SIZES_SED) $(SIZES_NUMFMT)
 
@@ -272,7 +272,15 @@ $(VV)mkdir -p $(dir $(LDTIMEOBJ))
 @# Pipe a line of code defining _PROS_COMPILE_TOOLSTAMP and _PROS_COMPILE_DIRECTORY into GCC,
 @# which allows compilation from stdin. We define _PROS_COMPILE_DIRECTORY using a command line-defined macro
 @# which is the pwd | tail bit, which will truncate the path to the last 23 characters
-$(call test_output_2,Adding timestamp ,echo 'char const * const _PROS_COMPILE_TIMESTAMP = __DATE__ " " __TIME__; char const * const _PROS_COMPILE_DIRECTORY = "$(shell pwd | tail -c 23)";' | $(CC) -c -x c $(CFLAGS) $(EXTRA_CFLAGS) -o $(LDTIMEOBJ) -,$(OK_STRING))
+@# 
+@# const int _PROS_COMPILE_TIMESTAMP_INT = $(( $(date +%s) - $(date +%z) * 3600 ))
+@# char const * const _PROS_COMPILE_TIEMSTAMP = __DATE__ " " __TIME__
+@# char const * const _PROS_COMPILE_DIRECTORY = "$(shell pwd | tail -c 23)";
+@#
+@# The shell command $$(($$(date +%s)+($$(date +%-z)/100*3600))) fetches the current
+@# unix timestamp, and then adds the UTC timezone offset to account for time zones.
+
+$(call test_output_2,Adding timestamp ,echo 'const int _PROS_COMPILE_TIMESTAMP_INT = $(shell echo $$(($$(date +%s)+($$(date +%-z)/100*3600)))); char const * const _PROS_COMPILE_TIMESTAMP = __DATE__ " " __TIME__; char const * const _PROS_COMPILE_DIRECTORY = "$(shell pwd | tail -c 23)";' | $(CC) -c -x c $(CFLAGS) $(EXTRA_CFLAGS) -o $(LDTIMEOBJ) -,$(OK_STRING))
 endef
 
 # these rules are for build-compile-commands, which just print out sysroot information

diff --git a/include/pros/misc.h b/include/pros/misc.h
@@ -150,6 +150,25 @@ failed to connect or an invalid id is given.
 		errno = EACCES;						\
 		return PROS_ERR;					\
 	}										\
+/******************************************************************************/
+/**                              Date and Time                               **/
+/******************************************************************************/
+
+extern const char* baked_date;
+extern const char* baked_time;
+
+typedef struct {
+	uint16_t year; // Year - 1980
+	uint8_t day;
+	uint8_t month; // 1 = January
+} date_s_t;
+
+typedef struct {
+	uint8_t hour;
+	uint8_t min;
+	uint8_t sec;
+	uint8_t sec_hund; // hundredths of a second
+} time_s_t;
 
 #ifdef __cplusplus
 namespace c {

diff --git a/src/main.cpp b/src/main.cpp
@@ -87,6 +87,7 @@ void opcontrol() {
 
 		left_mtr = left;
 		right_mtr = right;
+
 		pros::delay(20);
 	}
 }
diff --git a/src/system/dev/ser_daemon.c b/src/system/dev/ser_daemon.c
@@ -27,6 +27,7 @@
 
 __attribute__((weak)) char const* const _PROS_COMPILE_TIMESTAMP = "Unknown";
 __attribute__((weak)) char const* const _PROS_COMPILE_DIRECTORY = "Unknown";
+__attribute__((weak)) const int         _PROS_COMPILE_TIMESTAMP_INT = 0;
 
 void print_small_banner(void) {
 	uint32_t uptime = millis();

diff --git a/src/system/hot.c b/src/system/hot.c
@@ -9,6 +9,9 @@ struct hot_table* const HOT_TABLE = &__HOT_TABLE;
 #define MAGIC0 0x52616368
 #define MAGIC1 0x8CEF7310
 
+extern void set_get_timestamp_int_func(const int (*func)(void));
+static const int get_timestamp_int(void);
+
 __attribute__((section(".hot_magic"))) uint32_t MAGIC[] = {MAGIC0, MAGIC1};
 uint32_t const volatile* const MAGIC_ADDR = MAGIC;
 
@@ -18,6 +21,7 @@ uint32_t const volatile* const MAGIC_ADDR = MAGIC;
 // regenerates that function with the call to the correct (user-written) C++ version
 extern char const* _PROS_COMPILE_TIMESTAMP;
 extern char const* _PROS_COMPILE_DIRECTORY;
+extern const int   _PROS_COMPILE_TIMESTAMP_INT;
 
 extern unsigned __exidx_start;
 extern unsigned __exidx_end;
@@ -63,6 +67,10 @@ __attribute__((section(".hot_init"))) void install_hot_table(struct hot_table* c
 	for (void (*const* ctor)() = __init_array_start; ctor < __init_array_end; ctor++) {
 		(*ctor)();
 	}
+
+	// Set the function pointer in newlib_stubs so that it can fetch the
+	// timestamp in the hot package. 
+	set_get_timestamp_int_func(get_timestamp_int);
 }
 
 // this function really exists on the cold section! Called by pros_init
@@ -78,3 +86,11 @@ void invoke_install_hot_table() {
 		memset(HOT_TABLE, 0, sizeof(*HOT_TABLE));
 	}
 }
+
+// This is a callback function used by newlib to get the unix timestamp
+// newlib cannot access any symbols in the hot package, so we have the hot
+// package pass a function pointer to this function. Newlib then uses that
+// function pointer. 
+static const int get_timestamp_int(void) {
+	return _PROS_COMPILE_TIMESTAMP_INT;
+}
diff --git a/src/system/newlib_stubs.c b/src/system/newlib_stubs.c
@@ -16,13 +16,19 @@
 
 #include <errno.h>
 #include <stdint.h>
+#include <sys/time.h>
 #include <unistd.h>
 #include <stdio.h>
 
 #include "rtos/task.h"
 #include "v5_api.h"
 
+#include "hot.h"
+#include "pros/misc.h"
+
 #define SEC_TO_MSEC 1000
+#define SEC_TO_MICRO 1000000
+#define MICRO_TO_NANO 1000
 
 void _exit(int status) {
 	if(status != 0) dprintf(3, "Error %d\n", status); // kprintf
@@ -56,3 +62,107 @@ int getentropy(void *_buffer, size_t _length) {
 void __sync_synchronize(void) {
 	__sync_synchronize();
 }
+
+// These variables are used to store the user-set time.
+// When user_time_set is false, the realtime clock will use the timestamp as the
+// base time. When it is true will use user_time_spec as the base time instead.
+// set_microseconds stores the value of the microsecond timer when the user set
+// the time.
+static bool user_time_set = false;
+static struct timespec user_time_spec;
+static int64_t set_microseconds = 0;
+
+int clock_settime(clockid_t clock_id, const struct timespec *tp) {
+	int retval = -1;
+
+	switch(clock_id) {
+	case CLOCK_REALTIME:
+		user_time_set = true;
+		user_time_spec	 = *tp;
+		set_microseconds = vexSystemHighResTimeGet();
+		retval = 0;
+	default:
+		errno = EINVAL;
+	}
+
+	return retval;
+}
+
+int clock_gettime(clockid_t clock_id, struct timespec* tp) {
+	struct timeval tv;
+	int retval = -1;
+
+	switch (clock_id)
+	{
+	case CLOCK_REALTIME:
+		retval = gettimeofday(&tv, NULL);
+		if (!retval) TIMEVAL_TO_TIMESPEC(&tv, tp);
+		break;
+	case CLOCK_MONOTONIC: {
+		uint64_t totalTime = vexSystemHighResTimeGet();
+		uint64_t secs = totalTime / SEC_TO_MICRO;
+		uint64_t micros = totalTime - secs * SEC_TO_MICRO;
+
+		tp->tv_sec = secs;
+		tp->tv_nsec = micros * MICRO_TO_NANO;
+		break;
+	}
+	default:
+		errno = EINVAL;
+		break;
+	}
+
+	return retval;
+}
+
+// HACK:
+//
+// This function pointer serves as a callback so that _gettimeofday() can call
+// a function inside the hot package. Without this, _gettimeofday() cannot
+// access any symbols in the hot package (where _PROS_COMPILE_TIMESTAMP_INT 
+// lives), and linker errors occur. 
+//
+// When the hot package is initialized, it calls set_get_timestamp_int_func()
+// and sets the callback to a function that returns the unix timestamp.
+//
+// Essentially, when the hot process starts:
+//   1) Pass the get_timestamp_int_func to the cold package
+//   2) When the cold package (this library) needs to access the timestamp,
+//      call the callback
+//   3) Then the cold package 
+static const int (*get_timestamp_int_func)(void) = NULL;
+
+void set_get_timestamp_int_func(const int (*func)(void))
+{
+	get_timestamp_int_func = func;
+}
+
+int _gettimeofday(struct timeval* tp, void* tzvp) {
+	if(get_timestamp_int_func == NULL) {
+		return -1;
+	}
+
+	if(user_time_set) {
+		tp->tv_sec = user_time_spec.tv_sec;
+		tp->tv_usec = user_time_spec.tv_nsec * 1000;
+		tp->tv_usec += vexSystemHighResTimeGet() - set_microseconds;
+	}
+	else if (competition_is_connected()) {
+		// TODO: update this to get the date/time through VexOS. Apparently,
+		// the time is kept properly only when competition controls are
+		// connected. I haven't had time to check or confirm this.
+		//https://github.com/purduesigbots/pros/pull/127#issuecomment-1095361338
+		tp->tv_sec = get_timestamp_int_func();
+		tp->tv_usec = vexSystemHighResTimeGet();
+	}
+	else {
+		// When competition isn't connected, the vex's date/time functions do
+		// not work. Here we use a timestamp compiled into the program and then
+		// add the number of microseconds the program has been running to get 
+		// the best estimate.
+		tp->tv_sec = get_timestamp_int_func();
+		tp->tv_usec = vexSystemHighResTimeGet();
+	}
+
+	return 1;
+}
diff --git a/version b/version
@@ -1 +1 @@
-3.7.1
+3.7.1