rtc fixes, time command

makefile

@@ -37,7 +37,7 @@ out/fs/bin/%: obj/%.elf
 
 out/fs: out/fs/bin/init     out/fs/bin/highway out/fs/bin/meminfo \
         out/fs/bin/terminal out/fs/bin/hello   out/fs/bin/mkpopup \
-        out/fs/bin/dirlist  out/fs/bin/ttt
+        out/fs/bin/dirlist  out/fs/bin/ttt     out/fs/bin/time
 	touch out/fs
 	cp -r fs-skel/* out/fs/
 
@@ -82,9 +82,10 @@ obj/c.rto: obj/runtimes/c/pcrt.ao
 obj/cpp.rto:
 	#TODO
 
-obj/knob.so: obj/knob/file.o  obj/knob/format.o obj/knob/rand.o \
+obj/knob.so: obj/knob/file.o  obj/knob/format.o obj/knob/rand.o  \
-             obj/knob/heap.o  obj/knob/ipc.o    obj/knob/task.o \
+             obj/knob/heap.o  obj/knob/ipc.o    obj/knob/task.o  \
-             obj/knob/block.o obj/knob/key.o    obj/knob/panic.o
+             obj/knob/block.o obj/knob/key.o    obj/knob/panic.o \
+             obj/knob/time.o
 	ld ${partlink} $^ -o $@
 
 obj/libterm.so: obj/libterm/terminal.o obj/libterm/termtask.o obj/libterm/readline.o
@@ -126,4 +127,8 @@ obj/dirlist.elf: obj/dirlist/main.o obj/libterm.so obj/knob.so \
 
 obj/ttt.elf : obj/ttt/main.o obj/popups.so obj/libfont.so \
               obj/knob.so obj/c.rto
+	ld -T src/user/runtimes/c/elf.ld $^ -o $@
+
+obj/time.elf: obj/time/time.o obj/libterm.so obj/knob.so \
+              obj/c.rto
 	ld -T src/user/runtimes/c/elf.ld $^ -o $@

src/kernel/cmos.c

@@ -3,9 +3,22 @@
 
 static inline uint8_t read_cmos(uint8_t reg) {
   outb(0x0070, reg);
+  for (uint32_t i = 0; i < 1000000; ++i)
+    ;//spin
   return inb(0x0071);
 }
 
+static inline void write_cmos(uint8_t reg, uint8_t value) {
+  outb(0x0070, reg);
+  for (uint32_t i = 0; i < 1000000; ++i)
+    ;//spin
+  outb(0x0071, value);
+}
+
+void cmos_init() {
+  write_cmos(0x0b, read_cmos(0x0b) | 0x06);
+}
+
 //The idea of reading until you get the same value twice, and checking the status register
 //  is from the OSDev Wiki page at <https://wiki.osdev.org/CMOS#The_Real-Time_Clock>.
 struct rtc_time get_rtc_time() {
@@ -21,11 +34,6 @@ get_sec:
   }
   ret.minutes      = read_cmos(0x02);
   ret.hours        = read_cmos(0x04);
-  if (ret.hours & 0x80) {
-    ret.hours -= 0x80 - 12;
-    if (ret.hours == 24)
-      ret.hours = 0;
-  }
   ret.day_of_week  = read_cmos(0x06);
   ret.day_of_month = read_cmos(0x07);
   ret.month        = read_cmos(0x08);

src/kernel/cmos.h

@@ -14,5 +14,6 @@ struct rtc_time {
 };
 
 struct rtc_time get_rtc_time();
+void cmos_init();
 
 #endif

src/kernel/main.c

@@ -23,6 +23,7 @@ void _start_user_mode() __attribute__ ((noreturn));
 
 __attribute__ ((noreturn))
 void main() {
+  cmos_init();
   init_pagemap();
   init_paging();
   init_tasks();

src/user/include/knob/time.h

@@ -0,0 +1,13 @@
+#include <stdint.h>
+
+struct time {
+  uint16_t year;//ad
+  uint8_t month;//jan = 1
+  uint8_t day;
+  uint8_t hour;//24-hour, midnight = 0
+  uint8_t minute;
+  uint8_t second;
+  uint32_t timestamp;
+};
+
+struct time get_time();

src/user/knob/time.c

@@ -0,0 +1,57 @@
+#include <pland/syscall.h>
+#include <knob/time.h>
+#include <stdint.h>
+
+uint8_t days_in_months[] = {
+  31,  0, 31, 30,
+  31, 30, 31, 31,
+  30, 31, 30, 31
+};
+
+struct time get_time() {
+  struct time t;
+
+  const uint32_t ts = _get_timestamp();
+  t.timestamp = ts;
+
+  const uint32_t time_part = ts % 86400;
+  t.hour = time_part / 3600;
+  t.minute = (time_part / 60) % 60;
+  t.second = time_part % 60;
+
+  uint32_t days = ts / 86400;
+
+  uint32_t year = 2000;
+  while (days >= 1461) {
+    year += 4;
+    days -= 1461;
+  }
+
+  days_in_months[1] = 28;
+  if (days >= 1096) {
+    t.year = year += 3;
+    days -= 1096;
+  }
+  else if (days >= 731) {
+    t.year = year += 2;
+    days -= 731;
+  }
+  else if (days >= 366) {
+    t.year = ++year;
+    days -= 366;
+  }
+  else {
+    t.year = year;
+    days_in_months[1] = 29;
+  }
+
+  uint8_t m = 0;
+  while (days >= days_in_months[m]) {
+    days -= days_in_months[m];
+    ++m;
+  }
+
+  t.month = m + 1;
+  t.day = days + 1;
+  return t;
+}

src/user/time/time.c

@@ -0,0 +1,24 @@
+#include <libterm/terminal.h>
+#include <knob/time.h>
+
+static const char *const month_names[] = {
+  "January",
+  "February",
+  "March",
+  "April",
+  "May",
+  "June",
+  "July",
+  "August",
+  "September",
+  "October",
+  "November",
+  "December"
+};
+
+void main() {
+  const struct time t = get_time();
+  term_addf("TS: 0x%8h\n", t.timestamp);
+  term_addf("Date: %s %u, %u\n", month_names[t.month - 1], t.day, t.year);
+  term_addf("Time: %u:%2u:%2u\n", t.hour, t.minute, t.second);
+}