Squash commits for public release

boot/x86_64/prekernel/drivers/port.h

@@ -0,0 +1,61 @@
+#ifndef _BOOT_DRIVERS_PORT_H
+#define _BOOT_DRIVERS_PORT_H
+
+#include <libboot/types.h>
+
+static inline uint8_t port_read8(uint16_t port)
+{
+    uint8_t result_data;
+    asm volatile("inb %%dx, %%al"
+                 : "=a"(result_data)
+                 : "d"(port));
+    return result_data;
+}
+
+static inline void port_write8(uint16_t port, uint8_t data)
+{
+    asm volatile("outb %%al, %%dx"
+                 :
+                 : "a"(data), "d"(port));
+}
+
+static inline uint16_t port_read16(uint16_t port)
+{
+    uint16_t result_data;
+    asm volatile("inw %%dx, %%ax"
+                 : "=a"(result_data)
+                 : "d"(port));
+    return result_data;
+}
+
+static inline void port_write16(uint16_t port, uint16_t data)
+{
+    asm volatile("outw %%ax, %%dx"
+                 :
+                 : "a"(data), "d"(port));
+}
+
+static inline uint32_t port_read32(uint16_t port)
+{
+    uint32_t result_data;
+    asm volatile("inl %%dx, %%eax"
+                 : "=a"(result_data)
+                 : "d"(port));
+    return result_data;
+}
+
+static inline void port_write32(uint16_t port, uint32_t data)
+{
+    asm volatile("outl %%eax, %%dx"
+                 :
+                 : "a"(data), "d"(port));
+}
+
+static inline void port_wait_io()
+{
+    asm volatile("out %%al, $0x80"
+                 :
+                 : "a"(0));
+}
+
+#endif // _BOOT_DRIVERS_PORT_H

boot/x86_64/prekernel/drivers/uart.c

@@ -0,0 +1,43 @@
+#include "uart.h"
+#include "port.h"
+
+static int _uart_setup_impl(int port)
+{
+    port_write8(port + 1, 0x00);
+    port_write8(port + 3, 0x80);
+    port_write8(port + 0, 0x03);
+    port_write8(port + 1, 0x00);
+    port_write8(port + 3, 0x03);
+    port_write8(port + 2, 0xC7);
+    port_write8(port + 4, 0x0B);
+    return 0;
+}
+
+void uart_init()
+{
+    _uart_setup_impl(COM1);
+}
+
+static inline bool _uart_is_free_in(int port)
+{
+    return port_read8(port + 5) & 0x01;
+}
+
+static inline bool _uart_is_free_out(int port)
+{
+    return port_read8(port + 5) & 0x20;
+}
+
+int uart_write(uint8_t data)
+{
+    while (!_uart_is_free_out(COM1)) { }
+    port_write8(COM1, data);
+    return 0;
+}
+
+int uart_read(uint8_t* data)
+{
+    while (!_uart_is_free_out(COM1)) { }
+    *data = port_read8(COM1);
+    return 0;
+}

boot/x86_64/prekernel/drivers/uart.h

@@ -0,0 +1,15 @@
+#ifndef _BOOT_DRIVERS_UART_H
+#define _BOOT_DRIVERS_UART_H
+
+#include <libboot/types.h>
+
+#define COM1 0x3F8
+#define COM2 0x2F8
+#define COM3 0x3E8
+#define COM4 0x2E8
+
+void uart_init();
+int uart_write(uint8_t data);
+int uart_read(uint8_t* data);
+
+#endif //_BOOT_DRIVERS_UART_H