Add existing drivers

Makefile.am

@@ -8,4 +8,18 @@ SUBDIRS = include
 lib_LTLIBRARIES = libdrivers.la
 
 libdrivers_la_SOURCES = \
-	src/foobar.c
+	src/foobar.c \
+	src/console.c \
+	src/shutdown.c
+
+# Intel 8253-compatible programmable interval timer
+
+if ASM_I386
+libdrivers_la_SOURCES += src/intel_8253_pit.c
+endif
+
+# Intel 8259-compatible programmable interrupt controller
+
+if ASM_I386
+libdrivers_la_SOURCES += src/intel_8259_pic.c
+endif

include/Makefile.am

@@ -1,2 +1,16 @@
 nobase_include_HEADERS = \
-	drivers.h
+	drivers.h \
+	drivers/console.h \
+	drivers/shutdown.h
+
+# Intel 8253-compatible programmable interval timer
+
+if ASM_I386
+nobase_include_HEADERS += drivers/intel_8253_pit.h
+endif
+
+# Intel 8259-compatible programmable interrupt controller
+
+if ASM_I386
+nobase_include_HEADERS += drivers/intel_8259_pic.h
+endif

include/drivers/console.h

@@ -0,0 +1,20 @@
+#ifndef INCLUDED_DRIVERS_CONSOLE
+#define INCLUDED_DRIVERS_CONSOLE
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+
+void drivers_console_putc(char c);
+
+void drivers_console_print(const char *s);
+void drivers_console_puts(const char *s);
+void drivers_console_write(const char *data, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

include/drivers/intel_8253_pit.h

@@ -0,0 +1,21 @@
+/**
+ * @brief A driver for Intel 8253-compatible programmable interval timer
+ *
+ * @see https://en.wikipedia.org/wiki/Intel_8253
+ * @see https://wiki.osdev.org/PIT
+ */
+
+#ifndef DRIVERS_INCLUDED_INTEL_8253_PIT
+#define DRIVERS_INCLUDED_INTEL_8253_PIT
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void drivers_intel_8253_pit_initialize(unsigned int freq);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

include/drivers/intel_8259_pic.h

@@ -0,0 +1,57 @@
+/**
+ * @brief A driver for Intel 8259-compatible programmable interrupt controller
+ *
+ * @details
+ * This is not a driver for a random Intel 8259-compatible PIC, but only for a
+ * typical configuration of it that can be found in most PCs.
+ *
+ * @see https://en.wikipedia.org/wiki/Intel_8259
+ * @see https://wiki.osdev.org/8259_PIC
+ * @see https://pdos.csail.mit.edu/6.828/2005/readings/hardware/8259A.pdf
+ */
+
+#ifndef DRIVERS_INCLUDED_INTEL_8259_PIC
+#define DRIVERS_INCLUDED_INTEL_8259_PIC
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Enable PIC
+ */
+void drivers_intel_8259_pic_enable_all();
+
+/**
+ * @brief Disable PIC
+ */
+void drivers_intel_8259_pic_disable_all();
+
+/**
+ * @brief Enable single IRQ line
+ */
+void drivers_intel_8259_pic_enable(unsigned char number);
+
+/**
+ * @brief Disable single IRQ line
+ */
+void drivers_intel_8259_pic_disable(unsigned char number);
+
+/**
+ * @brief Remap PIC
+ */
+void drivers_intel_8259_pic_remap(
+    unsigned char new_master_start,
+    unsigned char new_slave_start
+);
+
+/**
+ * @brief Signal end of interrupt
+ */
+void drivers_intel_8259_pic_eoi(unsigned char number);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

include/drivers/shutdown.h

@@ -0,0 +1,15 @@
+#ifndef DRIVERS_INCLUDED_SHUTDOWN
+#define DRIVERS_INCLUDED_SHUTDOWN
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+__attribute__((noreturn)) void drivers_shutdown_halt();
+__attribute__((noreturn)) void drivers_shutdown_poweroff();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/console.c

@@ -0,0 +1,36 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <drivers/console.h>
+
+#include <stddef.h>
+
+void drivers_console_putc(const char c)
+{
+#if defined(ASM_X86)
+    __asm__ __volatile__("outb %1, %0" : : "dN" (0x3f8), "a" (c));
+#else
+    (void)c;
+#endif
+}
+
+void drivers_console_print(const char *const s)
+{
+    for (const char *c = s; *c; ++c) {
+        drivers_console_putc(*c);
+    }
+}
+
+void drivers_console_puts(const char *const s)
+{
+    drivers_console_print(s);
+    drivers_console_putc('\n');
+}
+
+void drivers_console_write(const char *const data, const size_t size)
+{
+    for (size_t i = 0; i < size; i++) {
+        drivers_console_putc(data[i]);
+    }
+}

src/intel_8253_pit.c

@@ -0,0 +1,19 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <drivers/intel_8253_pit.h>
+
+#include <stdint.h>
+
+void drivers_intel_8253_pit_initialize(const unsigned int freq)
+{
+    const unsigned int divisor = 1193180 / freq;
+
+    const uint8_t l = divisor & 0xff;
+    const uint8_t h = (divisor >> 8) & 0xff;
+
+    __asm__ __volatile__("outb %1, %0" : : "dN" (0x43), "a" (0x36));
+    __asm__ __volatile__("outb %1, %0" : : "dN" (0x40), "a" (l));
+    __asm__ __volatile__("outb %1, %0" : : "dN" (0x40), "a" (h));
+}

src/intel_8259_pic.c

@@ -0,0 +1,112 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <drivers/intel_8259_pic.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define BITS8(n)  ((uint8_t )(((uint8_t )1) << (n)))
+
+#define MASTER_COMMAND_PORT 0x20
+#define SLAVE_COMMAND_PORT  0xA0
+
+#define MASTER_DATA_PORT 0x21
+#define SLAVE_DATA_PORT  0xA1
+
+#define IRQS_COUNT 8
+#define IRQS_TOTAL 16
+
+static unsigned char master_start = 0;
+static unsigned char slave_start  = 8;
+
+static uint8_t inportb(const uint16_t port)
+{
+    register uint8_t result;
+    __asm__ __volatile__("inb %1, %0" : "=a" (result) : "dN" (port));
+    return result;
+}
+
+
+static void outportb(const uint16_t port, const uint8_t value)
+{
+    __asm__ __volatile__("outb %1, %0" : : "dN" (port), "a" (value));
+}
+
+void drivers_intel_8259_pic_enable_all()
+{
+    outportb(MASTER_DATA_PORT, 0);
+    outportb(SLAVE_DATA_PORT,  0);
+}
+
+void drivers_intel_8259_pic_disable_all()
+{
+    outportb(MASTER_DATA_PORT, 0xFF);
+    outportb(SLAVE_DATA_PORT,  0xFF);
+}
+
+void drivers_intel_8259_pic_enable(const unsigned char number)
+{
+    if (number < IRQS_COUNT) {
+        const uint8_t mask = inportb(MASTER_DATA_PORT);
+        outportb(MASTER_DATA_PORT, mask & ~BITS8(number));
+    } else {
+        const uint8_t mask = inportb(SLAVE_DATA_PORT);
+        outportb(SLAVE_DATA_PORT, mask & ~BITS8((number - IRQS_COUNT)));
+    }
+}
+
+void drivers_intel_8259_pic_disable(const unsigned char number)
+{
+    if (number < IRQS_COUNT) {
+        const uint8_t mask = inportb(MASTER_DATA_PORT);
+        outportb(MASTER_DATA_PORT, mask | BITS8(number));
+    } else {
+        const uint8_t mask = inportb(SLAVE_DATA_PORT);
+        outportb(SLAVE_DATA_PORT, mask | BITS8((number - IRQS_COUNT)));
+    }
+}
+
+void drivers_intel_8259_pic_remap(
+    const unsigned char new_master_start,
+    const unsigned char new_slave_start
+) {
+    master_start = new_master_start;
+    slave_start  = new_slave_start;
+
+    // Save masks
+    const uint8_t master_mask = inportb(MASTER_DATA_PORT);
+    const uint8_t slave_mask  = inportb(SLAVE_DATA_PORT);
+
+    // Start the initialization sequence
+    outportb(MASTER_COMMAND_PORT, 0x11);
+    outportb(SLAVE_COMMAND_PORT,  0x11);
+
+    // Set IRQ vectors
+    outportb(MASTER_DATA_PORT, new_master_start);
+    outportb(SLAVE_DATA_PORT,  new_slave_start);
+
+    // Connect master and slave with each other
+    outportb(MASTER_DATA_PORT, 0x04);
+    outportb(SLAVE_DATA_PORT,  0x02);
+
+    // 8086/88 (MCS-80/85) mode
+    outportb(MASTER_DATA_PORT, 0x01);
+    outportb(SLAVE_DATA_PORT,  0x01);
+
+    // Restore masks
+    outportb(MASTER_DATA_PORT, master_mask);
+    outportb(SLAVE_DATA_PORT,  slave_mask);
+}
+
+void drivers_intel_8259_pic_eoi(const unsigned char number)
+{
+    const bool to_slave =
+        number >= slave_start && number < slave_start + IRQS_COUNT;
+    const bool to_master = to_slave ||
+        (number >= master_start && number < master_start + IRQS_COUNT);
+
+    if (to_slave)  outportb(SLAVE_COMMAND_PORT,  0x20);
+    if (to_master) outportb(MASTER_COMMAND_PORT, 0x20);
+}

src/shutdown.c

@@ -0,0 +1,29 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <drivers/shutdown.h>
+
+void drivers_shutdown_halt()
+{
+#ifdef ASM_X86
+    // Disable interrupts
+    __asm__ __volatile__("cli");
+#endif
+
+    volatile int x = 0;
+    for (;;) ++x;
+}
+
+void drivers_shutdown_poweroff()
+{
+#ifdef ASM_X86
+    // QEMU >= 2.0
+    __asm__ __volatile__("outw %1, %0" : : "dN" (0x604), "a" (0x2000));
+    // QEMU < 2.0
+    __asm__ __volatile__("outw %1, %0" : : "dN" (0xB004), "a" (0x2000));
+#endif
+
+    // If we can't poweroff then we halt
+    drivers_shutdown_halt();
+}