ps2 init complete, can receive keyboard presses

kernel/drivers/ps2/ps2.c

@@ -0,0 +1,70 @@
+#include <stdint.h>
+#include <drivers/ps2/ps2.h>
+
+extern void ps2_wait_input_empty(void);
+extern void ps2_wait_output_full(void);
+extern void ps2_write_command(uint8_t);
+extern uint8_t ps2_read_data(void);
+extern void ps2_write_data(uint8_t);
+extern void ps2_flush_output_buffer(void);
+
+extern void io_wait(void);
+
+static uint8_t read_ccb() {
+    ps2_write_command(CMD_READ_CCB);
+    io_wait();
+    return ps2_read_data();
+}
+
+static void write_ccb(uint8_t ccb) {
+    ps2_write_command(CMD_WRITE_CCB);
+    io_wait();
+    ps2_write_data(ccb);
+    io_wait();
+}
+
+static int perform_self_test() {
+    ps2_write_command(CMD_SELF_TEST);
+    io_wait();
+    return ps2_read_data();
+}
+
+static int test_port_1() {
+    ps2_write_command(CMD_TEST_P1);
+    io_wait();
+    return ps2_read_data();
+}
+
+static void enable_port_1() {
+    ps2_write_command(CMD_ENABLE_P1);
+    io_wait();
+}
+
+int init_ps2() {
+    ps2_write_command(CMD_DISABLE_P1);
+    ps2_write_command(CMD_DISABLE_P2);
+
+    ps2_flush_output_buffer();
+
+    uint8_t ccb = read_ccb();
+    ccb = ccb & 0xEC;
+    write_ccb(ccb);
+
+    int result = perform_self_test();
+    if (result != SELF_TEST_SUCCESS) {
+        return -1;
+    }
+
+    result = test_port_1();
+    if (result != PORT_TEST_SUCCESS) {
+        return -1;
+    }
+
+    enable_port_1();
+
+    ccb = read_ccb();
+    ccb |= 0x01;    // this enables interrupts for port 1, which we want
+    write_ccb(ccb);
+
+    return 0;
+}   

kernel/drivers/ps2/ps2.h

@@ -0,0 +1,19 @@
+#ifndef KPS2_H
+#define KPS2_H
+
+#define PS2_DATA 0x60 
+#define PS2_STATUS 0x64 
+#define PS2_COMMAND 0x64
+
+#define CMD_DISABLE_P1  0xAD
+#define CMD_DISABLE_P2  0xAE
+#define CMD_READ_CCB    0x20
+#define CMD_WRITE_CCB   0x60
+#define CMD_SELF_TEST   0xAA
+#define CMD_TEST_P1     0xAB
+#define CMD_ENABLE_P1   0xAE
+
+#define SELF_TEST_SUCCESS 0x55 
+#define PORT_TEST_SUCCESS 0x00
+
+#endif

kernel/drivers/ps2/ps2_stubs.S

@@ -0,0 +1,87 @@
+#include "drivers/ps2/ps2.h"
+
+.code32 
+
+.global ps2_wait_input_empty 
+.global ps2_wait_output_full
+.global ps2_write_command
+.global ps2_read_data
+.global ps2_write_data
+.global ps2_flush_output_buffer
+
+.extern io_wait
+
+# helpers
+ps2_wait_input_empty: #(void) -> void
+    push %ebp
+    mov %esp, %ebp
+1:  
+    inb $PS2_STATUS, %al
+    andb $0x02, %al
+    jnz 1b
+
+    leave
+    ret
+
+ps2_wait_output_full: #(void) -> void
+    push %ebp
+    mov %esp, %ebp 
+1:
+    inb $PS2_STATUS, %al
+    andb $0x01, %al
+    jz 1b
+
+    leave
+    ret
+
+ps2_write_command: #(uint8_t command) -> void
+    push %ebp
+    mov %esp, %ebp
+
+    call ps2_wait_input_empty
+
+    xor %eax, %eax
+    movb 8(%ebp), %al
+    outb %al, $PS2_COMMAND
+
+    leave
+    ret
+
+ps2_read_data: #(void) -> uint8_t
+    push %ebp
+    mov %esp, %ebp
+
+    call ps2_wait_output_full 
+
+    xor %eax, %eax
+    inb $PS2_DATA, %al
+
+    leave
+    ret
+
+ps2_write_data: #(uint8_t) -> void
+    push %ebp 
+    mov %esp, %ebp
+
+    call ps2_wait_input_empty
+    
+    xor %eax, %eax
+    movb 8(%ebp), %al
+    outb %al, $PS2_DATA
+
+    leave
+    ret
+
+
+ps2_flush_output_buffer: #(void) -> void
+    push %ebp
+    mov %esp, %ebp
+1:
+    inb $PS2_STATUS, %al
+    andb $0x01, %al
+    jz 2f
+    inb $PS2_DATA, %al
+    jmp 1b
+2:  
+    leave
+    ret