From 38fcbfeebc7ce9c1aa940c1b98f6141f161a6ff4 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 25 Feb 2008 22:30:47 -0500
Subject: Version 0.1.2

---
 src/serial.c | 209 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 209 insertions(+)

(limited to 'src/serial.c')

diff --git a/src/serial.c b/src/serial.c
index 5541089..63d1766 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -8,11 +8,210 @@
 #include "biosvar.h" // struct bregs
 #include "util.h" // debug_enter
 
+
+/****************************************************************
+ * COM ports
+ ****************************************************************/
+
+static u16
+getComAddr(struct bregs *regs)
+{
+    if (regs->dx >= 4) {
+        set_cf(regs, 1);
+        return 0;
+    }
+    u16 addr = GET_BDA(port_com[regs->dx]);
+    if (! addr)
+        set_cf(regs, 1);
+    return addr;
+}
+
+static void
+handle_1400(struct bregs *regs)
+{
+    u16 addr = getComAddr(regs);
+    if (!addr)
+        return;
+    outb(inb(addr+3) | 0x80, addr+3);
+    if ((regs->al & 0xE0) == 0) {
+        outb(0x17, addr);
+        outb(0x04, addr+1);
+    } else {
+        u16 val16 = 0x600 >> ((regs->al & 0xE0) >> 5);
+        outb(val16 & 0xFF, addr);
+        outb(val16 >> 8, addr+1);
+    }
+    outb(regs->al & 0x1F, addr+3);
+    regs->ah = inb(addr+5);
+    regs->al = inb(addr+6);
+    set_cf(regs, 0);
+}
+
+static void
+handle_1401(struct bregs *regs)
+{
+    u16 addr = getComAddr(regs);
+    if (!addr)
+        return;
+    u16 timer = GET_BDA(timer_counter);
+    u16 timeout = GET_BDA(com_timeout[regs->dx]);
+    while (((inb(addr+5) & 0x60) != 0x60) && (timeout)) {
+        u16 val16 = GET_BDA(timer_counter);
+        if (val16 != timer) {
+            timer = val16;
+            timeout--;
+        }
+    }
+    if (timeout)
+        outb(regs->al, addr);
+    regs->ah = inb(addr+5);
+    if (!timeout)
+        regs->ah |= 0x80;
+    set_cf(regs, 0);
+}
+
+static void
+handle_1402(struct bregs *regs)
+{
+    u16 addr = getComAddr(regs);
+    if (!addr)
+        return;
+    u16 timer = GET_BDA(timer_counter);
+    u16 timeout = GET_BDA(com_timeout[regs->dx]);
+    while (((inb(addr+5) & 0x01) == 0) && (timeout)) {
+        u16 val16 = GET_BDA(timer_counter);
+        if (val16 != timer) {
+            timer = val16;
+            timeout--;
+        }
+    }
+    if (timeout) {
+        regs->ah = 0;
+        regs->al = inb(addr);
+    } else {
+        regs->ah = inb(addr+5);
+    }
+    set_cf(regs, 0);
+}
+
+static void
+handle_1403(struct bregs *regs)
+{
+    u16 addr = getComAddr(regs);
+    if (!addr)
+        return;
+    regs->ah = inb(addr+5);
+    regs->al = inb(addr+6);
+    set_cf(regs, 0);
+}
+
+static void
+handle_14XX(struct bregs *regs)
+{
+    // Unsupported
+    set_cf(regs, 1);
+}
+
 // INT 14h Serial Communications Service Entry Point
 void VISIBLE
 handle_14(struct bregs *regs)
 {
     debug_enter(regs);
+
+    irq_enable();
+
+    switch (regs->ah) {
+    case 0x00: handle_1400(regs); break;
+    case 0x01: handle_1401(regs); break;
+    case 0x02: handle_1402(regs); break;
+    case 0x03: handle_1403(regs); break;
+    default:   handle_14XX(regs); break;
+    }
+    debug_exit(regs);
+}
+
+
+/****************************************************************
+ * LPT ports
+ ****************************************************************/
+
+static u16
+getLptAddr(struct bregs *regs)
+{
+    if (regs->dx >= 3) {
+        set_cf(regs, 1);
+        return 0;
+    }
+    u16 addr = GET_BDA(port_lpt[regs->dx]);
+    if (! addr)
+        set_cf(regs, 1);
+    return addr;
+}
+
+static void
+lpt_ret(struct bregs *regs, u16 addr, u16 timeout)
+{
+    u8 val8 = inb(addr+1);
+    regs->ah = (val8 ^ 0x48);
+    if (!timeout)
+        regs->ah |= 0x01;
+    set_cf(regs, 0);
+}
+
+// INT 17 - PRINTER - WRITE CHARACTER
+static void
+handle_1700(struct bregs *regs)
+{
+    u16 addr = getLptAddr(regs);
+    if (!addr)
+        return;
+    u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
+
+    outb(regs->al, addr);
+    u8 val8 = inb(addr+2);
+    outb(val8 | 0x01, addr+2); // send strobe
+    nop();
+    outb(val8 & ~0x01, addr+2);
+    while (((inb(addr+1) & 0x40) == 0x40) && (timeout))
+        timeout--;
+
+    lpt_ret(regs, addr, timeout);
+}
+
+// INT 17 - PRINTER - INITIALIZE PORT
+static void
+handle_1701(struct bregs *regs)
+{
+    u16 addr = getLptAddr(regs);
+    if (!addr)
+        return;
+    u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
+
+    u8 val8 = inb(addr+2);
+    outb(val8 & ~0x04, addr+2); // send init
+    nop();
+    outb(val8 | 0x04, addr+2);
+
+    lpt_ret(regs, addr, timeout);
+}
+
+// INT 17 - PRINTER - GET STATUS
+static void
+handle_1702(struct bregs *regs)
+{
+    u16 addr = getLptAddr(regs);
+    if (!addr)
+        return;
+    u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
+
+    lpt_ret(regs, addr, timeout);
+}
+
+static void
+handle_17XX(struct bregs *regs)
+{
+    // Unsupported
+    set_cf(regs, 1);
 }
 
 // INT17h : Printer Service Entry Point
@@ -20,4 +219,14 @@ void VISIBLE
 handle_17(struct bregs *regs)
 {
     debug_enter(regs);
+
+    irq_enable();
+
+    switch (regs->ah) {
+    case 0x00: handle_1700(regs); break;
+    case 0x01: handle_1701(regs); break;
+    case 0x02: handle_1702(regs); break;
+    default:   handle_17XX(regs); break;
+    }
+    debug_exit(regs);
 }
-- 
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