x86_64: re-enable legacy PIC and PIT initialisation

arch/x86_64/extra.mk

@@ -4,10 +4,7 @@ QEMU_MONITOR_FLAGS := -serial stdio
 QEMU_FLAGS := \
 	-m 10M \
 	-display sdl \
-	-smp 4 -cpu qemu64,pdpe1gb \
-	-device ahci,id=ahci \
-	-drive id=hd0,file=$(BUILD_DIR)/disk.img,if=none -device ide-hd,drive=hd0,bus=ahci.0 \
-	-drive id=cd0,file=$(BUILD_DIR)/disk2.img,if=none -device ide-cd,drive=cd0,bus=ahci.1
+	-smp 4 -cpu qemu64,pdpe1gb
 
 ARCH_TEMP_FILES := $(BUILD_DIR)/$(KERNEL_EXEC).elf32
 

arch/x86_64/include/arch/serial.h

@@ -0,0 +1,27 @@
+#ifndef ARCH_SERIAL_H_
+#define ARCH_SERIAL_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SERIAL_PORT_A 0x3F8
+#define SERIAL_PORT_B 0x2F8
+#define SERIAL_PORT_C 0x3E8
+#define SERIAL_PORT_D 0x2E8
+
+extern void serial_putchar(int port, char ch);
+
+extern void serial_wait(int device);
+extern void serial_send_byte(int device, char out);
+extern char serial_recv_byte(int device);
+
+extern int serial_rcvd(int device);
+
+extern void early_serialcon_init(int baud);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

arch/x86_64/init.c

@@ -1,4 +1,7 @@
+#include "arch/serial.h"
+
 #include <arch/e820.h>
+#include <arch/pit.h>
 #include <socks/arg.h>
 #include <socks/clock.h>
 #include <socks/console.h>
@@ -49,12 +52,15 @@ void early_console_init(void)
 {
 	const char *dest = arg_value("kernel.early-console");
 	if (!dest) {
-		return;
-	}
+		dest = "ttyS0";
 	}
 
-static void init_bootfb(multiboot_info_t *mb)
-{
+	if (!strcmp(dest, "tty0")) {
+		/* show log messages on VGA */
+	} else if (!strcmp(dest, "ttyS0")) {
+		/* write log messages to serial port */
+		early_serialcon_init(115200);
+	}
 }
 
 static void use_uniprocessor_topology(void)
@@ -69,19 +75,14 @@ int ml_init(uintptr_t arg)
 
 	parse_cmdline(PTR32(mb->cmdline));
 
-	init_bootfb(mb);
+	early_console_init();
 
 	bootstrap_cpu_init();
 	clock_calibrate(500);
 
-	early_console_init();
-
 	print_kernel_banner();
 
 	early_vm_init();
-	printk("video mode: %ux%u",
-	       mb->framebuffer_width,
-	       mb->framebuffer_height);
 
 	e820_scan(PTR32(mb->mmap_addr), mb->mmap_length);
 
@@ -118,6 +119,7 @@ int ml_init(uintptr_t arg)
 
 	sched_init();
 
+	pit_start(500);
 	ml_int_enable();
 
 	return 0;

arch/x86_64/irq.c

@@ -10,7 +10,7 @@
 
 #define MAX_ISR_HANDLERS 16
 
-extern void syscall_gate();
+extern void syscall_gate(void);
 extern uintptr_t pf_faultptr(void);
 
 static int_hook isr_handlers[NR_IDT_ENTRIES];
@@ -92,7 +92,7 @@ static void set_syscall_gate(uintptr_t rip)
 }
 #endif
 
-static void init_pic()
+static void init_pic(void)
 {
 	// Remap the PIC
 	outportb(0x20, 0x11);

arch/x86_64/pit.c

@@ -1,8 +1,8 @@
-#include <socks/printk.h>
+#include <arch/irq.h>
+#include <arch/ports.h>
 #include <socks/clock.h>
 #include <socks/cpu.h>
-#include <arch/ports.h>
-#include <arch/irq.h>
+#include <socks/printk.h>
 
 #define PIT_COUNTER0  0x40
 #define PIT_CMD       0x43
@@ -29,7 +29,6 @@
 
 #define PIT_FREQUENCY 1193182
 
-
 static volatile unsigned long long ticks = 0;
 
 static int pit_callback(void)
@@ -40,9 +39,7 @@ static int pit_callback(void)
 	return 0;
 }
 
-static struct irq_hook pit_irq_hook = {
-	.irq_callback = pit_callback
-};
+static struct irq_hook pit_irq_hook = {.irq_callback = pit_callback};
 
 void pit_start(unsigned int hz)
 {

arch/x86_64/serial.c

@@ -0,0 +1,166 @@
+#include <arch/irq.h>
+#include <arch/ports.h>
+#include <arch/serial.h>
+#include <socks/device.h>
+#include <socks/kext.h>
+#include <socks/libc/stdio.h>
+#include <socks/printk.h>
+#include <socks/tty.h>
+
+#define COM1 0x3F8
+#define COM2 0x2F8
+#define COM3 0x3E8
+#define COM4 0x2E8
+
+static int transmit_empty(int device)
+{
+	return inportb(device + 5) & 0x20;
+}
+
+static int serial_received(int device)
+{
+	return inportb(device + 5) & 0x1;
+}
+
+void serial_send_byte(int device, char out)
+{
+	volatile unsigned int _count = 0;
+	while (!transmit_empty(device)) {
+		_count++;
+	}
+
+	outportb(device, out);
+
+	while (!transmit_empty(device)) {
+		_count++;
+	}
+}
+
+char serial_recv_byte(int device)
+{
+	volatile unsigned int _count = 0;
+	while (!serial_received(device)) {
+		_count++;
+	}
+
+	char c = inportb(device);
+
+	outportb(device + 5, inportb(device + 5) & ~0x1);
+
+	return c;
+}
+
+void serial_putchar(int port, char ch)
+{
+	if (ch == '\n') {
+		serial_send_byte(port, '\r');
+	}
+
+	serial_send_byte(port, ch);
+}
+
+void serialcon_write(struct console *con, const char *s, unsigned int len)
+{
+	for (unsigned int i = 0; i < len; i++) {
+		serial_putchar(COM1, s[i]);
+	}
+}
+
+static int get_baud_divisor(int baud)
+{
+	int freq = 115200;
+	int best_baud = -1;
+	int best_div = -1;
+
+	for (int i = 1; i < 254; i++) {
+		int this_baud = freq / i;
+
+		if (this_baud == baud) {
+			return i;
+		}
+
+		if (best_baud == -1) {
+			best_baud = this_baud;
+			best_div = i;
+			continue;
+		}
+
+		if (this_baud < baud && best_baud > baud) {
+			/* TODO pick divisor that gives the closest baud rate */
+			return best_div;
+		}
+
+		best_baud = this_baud;
+		best_div = i;
+	}
+
+	return best_div;
+}
+
+static void init_serial_port(int port, int baud)
+{
+	int baud_div = get_baud_divisor(baud);
+	outportb(port + 1, 0x00);       // Disable all interrupts
+	outportb(port + 3, 0x80);       // Enable DLAB (set baud rate divisor)
+	outportb(port + 0, baud_div);   // Set divisor
+	outportb(port + 1, 0x00);
+	outportb(port + 3, 0x03);   // 8 bits, no parity, one stop bit
+	outportb(
+		port + 2,
+		0xC7);   // Enable FIFO, clear them, with 14-byte threshold
+	outportb(port + 4, 0x0B);   // IRQs enabled, RTS/DSR set
+	outportb(
+		port + 4,
+		0x1E);   // Set in loopback mode, test the serial chip
+	outportb(port + 0, 0xAE);   // Test serial chip (send byte 0xAE and
+	                            // check if serial returns same byte)
+
+	volatile unsigned int q = 0;
+	while (!serial_received(port)) {
+		q++;
+	}
+
+	// Check if serial is faulty (i.e: not same byte as sent)
+	if (inportb(port + 0) != 0xAE) {
+		return;
+	}
+
+	// If serial is not faulty set it in normal operation mode
+	// (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
+	outportb(port + 1, 0x01);
+	outportb(port + 4, 0x0F);
+	printk("serial: port %x initialised", port);
+}
+
+static struct console serialcon = {
+	.c_name = "serialcon",
+	.c_flags = CON_BOOT,
+	.c_write = serialcon_write,
+	.c_lock = SPIN_LOCK_INIT,
+};
+
+static int serial_irq1(void)
+{
+	if (serial_received(COM1)) {
+		unsigned char c = serial_recv_byte(COM1);
+		printk("serial: COM1 received %c", c);
+	}
+
+	if (serial_received(COM3)) {
+		unsigned char c = serial_recv_byte(COM3);
+		printk("serial: COM3 received %c", c);
+	}
+
+	return 0;
+}
+
+static struct irq_hook irq1_hook = {
+	.irq_callback = serial_irq1,
+};
+
+void early_serialcon_init(int baud)
+{
+	hook_irq(IRQ4, &irq1_hook);
+	init_serial_port(COM1, baud);
+	console_register(&serialcon);
+}