1 use system_error::SystemError;
2
3 use crate::{
4 arch::{io::PortIOArch, CurrentIrqArch, CurrentPortIOArch},
5 exception::InterruptArch,
6 };
7
8 pub struct RtcTime {
9 pub second: i32,
10 pub minute: i32,
11 pub hour: i32,
12 pub day: i32,
13 pub month: i32,
14 pub year: i32,
15 }
16
17 impl Default for RtcTime {
default() -> Self18 fn default() -> Self {
19 Self {
20 second: (0),
21 minute: (0),
22 hour: (0),
23 day: (0),
24 month: (0),
25 year: (0),
26 }
27 }
28 }
29
30 impl RtcTime {
31 ///@brief 从主板cmos中获取时间
32 ///
33 ///@param self time结构体
34 ///@return int 成功则为0
get(&mut self) -> Result<i32, SystemError>35 pub fn get(&mut self) -> Result<i32, SystemError> {
36 // 为防止中断请求打断该过程，需要先关中断
37 let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() };
38 //0x0B
39 let status_register_b: u8 = read_cmos(0x0B); // 读取状态寄存器B
40 let is_24h: bool = if (status_register_b & 0x02) != 0 {
41 true
42 } else {
43 false
44 }; // 判断是否启用24小时模式
45
46 let is_binary: bool = if (status_register_b & 0x04) != 0 {
47 true
48 } else {
49 false
50 }; // 判断是否为二进制码
51
52 loop {
53 self.year = read_cmos(CMOSTimeSelector::Year as u8) as i32;
54 self.month = read_cmos(CMOSTimeSelector::Month as u8) as i32;
55 self.day = read_cmos(CMOSTimeSelector::Day as u8) as i32;
56 self.hour = read_cmos(CMOSTimeSelector::Hour as u8) as i32;
57 self.minute = read_cmos(CMOSTimeSelector::Minute as u8) as i32;
58 self.second = read_cmos(CMOSTimeSelector::Second as u8) as i32;
59
60 if self.second == read_cmos(CMOSTimeSelector::Second as u8) as i32 {
61 break;
62 } // 若读取时间过程中时间发生跳变则重新读取
63 }
64
65 unsafe {
66 CurrentPortIOArch::out8(0x70, 0x00);
67 }
68
69 if !is_binary
70 // 把BCD转为二进制
71 {
72 self.second = (self.second & 0xf) + (self.second >> 4) * 10;
73 self.minute = (self.minute & 0xf) + (self.minute >> 4) * 10;
74 self.hour = ((self.hour & 0xf) + ((self.hour & 0x70) >> 4) * 10) | (self.hour & 0x80);
75 self.day = (self.day & 0xf) + ((self.day / 16) * 10);
76 self.month = (self.month & 0xf) + (self.month >> 4) * 10;
77 self.year = (self.year & 0xf) + (self.year >> 4) * 10;
78 }
79 self.year += 2000;
80
81 if (!is_24h) && (self.hour & 0x80) != 0 {
82 self.hour = ((self.hour & 0x7f) + 12) % 24;
83 } // 将十二小时制转为24小时
84
85 drop(irq_guard);
86
87 return Ok(0);
88 }
89 }
90
91 ///置位0x70的第7位，禁止不可屏蔽中断
92 #[inline]
read_cmos(addr: u8) -> u893 fn read_cmos(addr: u8) -> u8 {
94 unsafe {
95 CurrentPortIOArch::out8(0x70, 0x80 | addr);
96 return CurrentPortIOArch::in8(0x71);
97 }
98 }
99
100 /// used in the form of u8
101 #[repr(u8)]
102 enum CMOSTimeSelector {
103 Second = 0x00,
104 Minute = 0x02,
105 Hour = 0x04,
106 Day = 0x07,
107 Month = 0x08,
108 Year = 0x09,
109 }
110