Add a driver for Intel 8259-compatible PIC (#92)

include/kernaux/drivers/intel_8259_pic.h

@@ -1,3 +1,15 @@
+/**
+ * @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 KERNAUX_INCLUDED_DRIVERS_INTEL_8259_PIC
 #define KERNAUX_INCLUDED_DRIVERS_INTEL_8259_PIC
 
@@ -5,6 +17,39 @@
 extern "C" {
 #endif
 
+/**
+ * @brief Enable PIC
+ */
+void kernaux_drivers_intel_8259_pic_enable_all();
+
+/**
+ * @brief Disable PIC
+ */
+void kernaux_drivers_intel_8259_pic_disable_all();
+
+/**
+ * @brief Enable single IRQ line
+ */
+void kernaux_drivers_intel_8259_pic_enable(unsigned char number);
+
+/**
+ * @brief Disable single IRQ line
+ */
+void kernaux_drivers_intel_8259_pic_disable(unsigned char number);
+
+/**
+ * @brief Remap PIC
+ */
+void kernaux_drivers_intel_8259_pic_remap(
+    unsigned char new_master_start,
+    unsigned char new_slave_start
+);
+
+/**
+ * @brief Signal end of interrupt
+ */
+void kernaux_drivers_intel_8259_pic_eoi(unsigned char number);
+
 #ifdef __cplusplus
 }
 #endif

src/drivers/intel_8259_pic.c

@@ -2,7 +2,141 @@
 #include "config.h"
 #endif
 
+#include <kernaux/assert.h>
 #include <kernaux/drivers/intel_8259_pic.h>
 
-__attribute__((unused))
-static const int foobar = 0;
+#ifdef ASM_I386
+#include <kernaux/asm/i386.h>
+#endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#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
+
+#undef AVAILABLE
+#define NOT_AVAILABLE_MSG "Intel 8259-compatible PIC is not available"
+#ifdef ASM_I386
+#   define AVAILABLE
+#   define inportb  kernaux_asm_i386_inportb
+#   define outportb kernaux_asm_i386_outportb
+#endif
+
+static unsigned char master_start = 0;
+static unsigned char slave_start  = 8;
+
+void kernaux_drivers_intel_8259_pic_enable_all()
+{
+#ifndef AVAILABLE
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    outportb(MASTER_DATA_PORT, 0);
+    outportb(SLAVE_DATA_PORT,  0);
+#endif
+}
+
+void kernaux_drivers_intel_8259_pic_disable_all()
+{
+#ifndef AVAILABLE
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    outportb(MASTER_DATA_PORT, 0xFF);
+    outportb(SLAVE_DATA_PORT,  0xFF);
+#endif
+}
+
+void kernaux_drivers_intel_8259_pic_enable(const unsigned char number)
+{
+#ifndef AVAILABLE
+    (void)number;
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    KERNAUX_ASSERT(number < IRQS_TOTAL);
+
+    if (number < IRQS_COUNT) {
+        const uint8_t mask = inportb(MASTER_DATA_PORT);
+        outportb(MASTER_DATA_PORT, mask & ~(1 << number));
+    } else {
+        const uint8_t mask = inportb(SLAVE_DATA_PORT);
+        outportb(SLAVE_DATA_PORT, mask & ~(1 << (number - IRQS_COUNT)));
+    }
+#endif
+}
+
+void kernaux_drivers_intel_8259_pic_disable(const unsigned char number)
+{
+#ifndef AVAILABLE
+    (void)number;
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    KERNAUX_ASSERT(number < IRQS_TOTAL);
+
+    if (number < IRQS_COUNT) {
+        const uint8_t mask = inportb(MASTER_DATA_PORT);
+        outportb(MASTER_DATA_PORT, mask | (1 << number));
+    } else {
+        const uint8_t mask = inportb(SLAVE_DATA_PORT);
+        outportb(SLAVE_DATA_PORT, mask | (1 << (number - IRQS_COUNT)));
+    }
+#endif
+}
+
+void kernaux_drivers_intel_8259_pic_remap(
+    const unsigned char new_master_start,
+    const unsigned char new_slave_start
+) {
+#ifndef AVAILABLE
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    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);
+#endif
+}
+
+void kernaux_drivers_intel_8259_pic_eoi(const unsigned char number)
+{
+#ifndef AVAILABLE
+    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
+#else
+    KERNAUX_ASSERT(number < IRQS_TOTAL);
+
+    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);
+#endif
+}