Rewrite emulatorv1.0.0-alpha1

This is a complete rewrite and restructure of the entire emulator
project, as part of the effort in locking down the Bedrock specification
and in creating much better tooling for creating and using Bedrock
programs.

This commit adds a command-line argument scheme, an embedded assembler,
a headless emulator for use in non-graphical environments, deferred
window creation for programs that do not access the screen device,
and new versions of phosphor and bedrock-core. The new version of
phosphor supports multi-window programs, which will make it possible to
implement program forking in the system device later on, and the new
version of bedrock-core implements the final core specification.

1 files changed, 185 insertions, 0 deletions

diff --git a/src/devices/clock_device.rs b/src/devices/clock_device.rs
new file mode 100644
index 0000000..494e0c7
--- /dev/null
+++ b/src/devices/clock_device.rs
@@ -0,0 +1,185 @@
+use bedrock_core::*;
+
+use std::time::{Duration, Instant};
+
+
+macro_rules! now { () => {
+    time::OffsetDateTime::now_local()
+        .unwrap_or_else(|_| time::OffsetDateTime::now_utc())
+}; }
+
+fn current_year()   -> u8 { now!().year().saturating_sub(2000) as u8 }
+fn current_month()  -> u8 { now!().month() as u8 - 1 }
+fn current_day()    -> u8 { now!().day() as u8 - 1 }
+fn current_hour()   -> u8 { now!().hour() }
+fn current_minute() -> u8 { now!().minute() }
+fn current_second() -> u8 { now!().second() }
+
+macro_rules! fn_read_timer {
+    ($fn_name:ident($read:ident, $end:ident)) => {
+        pub fn $fn_name(&mut self) {
+            let uptime = self.uptime();
+            if self.$end > uptime {
+                self.$read = (self.$end.saturating_sub(uptime)) as u16;
+            } else {
+                if self.$end > 0 {
+                    self.$end = 0;
+                    self.wake = true;
+                }
+                self.$read = 0;
+            }
+        }
+    };
+}
+
+macro_rules! fn_set_timer {
+    ($fn_name:ident($write:ident, $end:ident)) => {
+        pub fn $fn_name(&mut self) {
+            let uptime = self.uptime();
+            if self.$write > 0 {
+                self.$end = uptime.saturating_add(self.$write as u32);
+            } else {
+                self.$end = 0;
+            }
+        }
+    };
+}
+
+
+pub struct ClockDevice {
+    pub wake: bool,
+
+    pub start: Instant,
+    pub uptime_read: u16,
+
+    pub t1_end: u32,
+    pub t2_end: u32,
+    pub t3_end: u32,
+    pub t4_end: u32,
+    pub t1_read: u16,
+    pub t2_read: u16,
+    pub t3_read: u16,
+    pub t4_read: u16,
+    pub t1_write: u16,
+    pub t2_write: u16,
+    pub t3_write: u16,
+    pub t4_write: u16,
+}
+
+impl ClockDevice {
+    pub fn new() -> Self {
+        Self {
+            start: Instant::now(),
+            uptime_read: 0,
+            wake: false,
+
+            t1_end: 0,
+            t2_end: 0,
+            t3_end: 0,
+            t4_end: 0,
+            t1_read: 0,
+            t2_read: 0,
+            t3_read: 0,
+            t4_read: 0,
+            t1_write: 0,
+            t2_write: 0,
+            t3_write: 0,
+            t4_write: 0,
+        }
+    }
+
+    pub fn uptime(&self) -> u32 {
+        (self.start.elapsed().as_millis() / 4) as u32
+    }
+
+    pub fn read_uptime(&mut self) {
+        self.uptime_read = self.uptime() as u16;
+    }
+
+    fn_read_timer!{ read_t1(t1_read, t1_end) }
+    fn_read_timer!{ read_t2(t2_read, t2_end) }
+    fn_read_timer!{ read_t3(t3_read, t3_end) }
+    fn_read_timer!{ read_t4(t4_read, t4_end) }
+
+    fn_set_timer!{ set_t1(t1_write, t1_end) }
+    fn_set_timer!{ set_t2(t2_write, t2_end) }
+    fn_set_timer!{ set_t3(t3_write, t3_end) }
+    fn_set_timer!{ set_t4(t4_write, t4_end) }
+
+
+    pub fn time_remaining(&mut self) -> Option<Duration> {
+        use std::cmp::max;
+        let uptime = self.uptime();
+
+        let end = max(self.t1_end, max(self.t2_end, max(self.t3_end, self.t4_end)));
+        let remaining = end.saturating_sub(uptime);
+        match remaining > 0 {
+            true => Some(Duration::from_millis(remaining as u64) * 4),
+            false => None,
+        }
+    }
+}
+
+impl Device for ClockDevice {
+    fn read(&mut self, port: u8) -> u8 {
+        match port {
+            0x0 => current_year(),
+            0x1 => current_month(),
+            0x2 => current_day(),
+            0x3 => current_hour(),
+            0x4 => current_minute(),
+            0x5 => current_second(),
+            0x6 => { self.read_uptime(); read_h!(self.uptime_read) },
+            0x7 => read_l!(self.uptime_read),
+            0x8 => { self.read_t1(); read_h!(self.t1_read) },
+            0x9 => read_l!(self.t1_read),
+            0xa => { self.read_t2(); read_h!(self.t2_read) },
+            0xb => read_l!(self.t2_read),
+            0xc => { self.read_t3(); read_h!(self.t3_read) },
+            0xd => read_l!(self.t3_read),
+            0xe => { self.read_t4(); read_h!(self.t4_read) },
+            0xf => read_l!(self.t4_read),
+            _ => unreachable!(),
+        }
+    }
+
+    fn write(&mut self, port: u8, value: u8) -> Option<Signal> {
+        match port {
+            0x0 => (),
+            0x1 => (),
+            0x2 => (),
+            0x3 => (),
+            0x4 => (),
+            0x5 => (),
+            0x6 => (),
+            0x7 => (),
+            0x8 => write_h!(self.t1_write, value),
+            0x9 => { write_l!(self.t1_write, value); self.set_t1() },
+            0xa => write_h!(self.t2_write, value),
+            0xb => { write_l!(self.t2_write, value); self.set_t2() },
+            0xc => write_h!(self.t3_write, value),
+            0xd => { write_l!(self.t3_write, value); self.set_t3() },
+            0xe => write_h!(self.t4_write, value),
+            0xf => { write_l!(self.t4_write, value); self.set_t4() },
+            _ => unreachable!(),
+        };
+        return None;
+    }
+
+    fn wake(&mut self) -> bool {
+        let uptime = self.uptime();
+        macro_rules! check_timer {
+            ($end:ident) => {
+                if self.$end > 0 && self.$end <= uptime {
+                    self.$end = 0;
+                    self.wake = true;
+                }
+            };
+        }
+        check_timer!(t1_end);
+        check_timer!(t2_end);
+        check_timer!(t3_end);
+        check_timer!(t4_end);
+        return std::mem::take(&mut self.wake);
+    }
+}