* initial posix_io support

msba2/drivers/Jamfile

@@ -3,4 +3,4 @@ SubDir TOP board msba2 drivers ;
 Module board_cc1100 : msba2-cc1100.c ;
 Module board_hal : msba2-hal.c ; 
 Module board_ltc4150 : msba2-ltc4150.c : gpioint ;
-Module board_common : msba2-uart0.c ;
+Module board_common : msba2-uart0.c msba2-uart0_thread.c : ringbuffer ;

msba2/drivers/include/uart0.h

@@ -0,0 +1,8 @@
+#ifndef __UART0_H
+#define __UART0_H 
+
+#define UART0_BUFSIZE 32
+
+extern int uart0_handler_pid;
+
+#endif /* __UART0_H */

msba2/drivers/msba2-uart0_thread.c

@@ -0,0 +1,101 @@
+#include <thread.h>
+#include <kernel.h>
+#include <msg.h>
+#include <board.h>
+#include <ringbuffer.h>
+
+#include <stdio.h>
+#include <errno.h>
+#include <irq.h>
+#include <posix_io.h>
+#include "uart0.h"
+
+//#define ENABLE_DEBUG
+#include <debug.h>
+
+static char buffer[UART0_BUFSIZE];
+ringbuffer uart0_ringbuffer;
+
+static void uart0_loop();
+
+void uart0_init() {
+    ringbuffer_init(&uart0_ringbuffer, buffer, UART0_BUFSIZE);
+    int pid = thread_create(KERNEL_CONF_STACKSIZE_MAIN, PRIORITY_MAIN-1, CREATE_STACKTEST, uart0_loop, "uart0");
+    uart0_handler_pid = pid;
+    puts("uart0_init() [OK]");
+}
+
+static int min(int a, int b) {
+    if (b>a) return a;
+    else return b;
+}
+
+static void uart0_loop() {
+    msg m;
+
+    int pid = thread_getpid();
+
+    int reader_pid = -1;
+    struct posix_iop *r = NULL;
+
+    puts("UART0 thread started.");
+
+    while (1) {
+        msg_receive(&m);
+
+        if (m.sender_pid == pid) {
+        } else {
+            switch (m.type) {
+                case OPEN:
+                    if (reader_pid == -1) {
+                        reader_pid = m.sender_pid;
+                        m.content.value = 0; // no error
+                    } else {
+                        m.content.value = -EBUSY;
+                    }
+                    msg_reply(&m,&m);
+                    break;
+                case READ:
+                    if (m.sender_pid != reader_pid) {
+                        m.content.value = -EINVAL;
+                        msg_reply(&m, &m);
+                    } else {
+                        r = (struct posix_iop *)m.content.ptr;
+                    }
+                    break;
+                case CLOSE:
+                    if (m.sender_pid == reader_pid) {
+                        DEBUG("uart0_thread: closing file from %i\n", reader_pid);
+                        reader_pid = -1;
+                        r = NULL;
+                        m.content.value = 0;
+                    } else {
+                        m.content.value = -EINVAL;
+                    }
+                    msg_reply(&m,&m);
+                    break;
+                default:
+                    m.content.value = -EINVAL;
+                    msg_reply(&m, &m);
+            }
+        }
+
+        if (uart0_ringbuffer.avail && (r != NULL)) {
+            int state = disableIRQ();
+            int nbytes = min(r->nbytes, uart0_ringbuffer.avail);
+            DEBUG("uart0_thread: sending %i bytes to pid %i\n", nbytes, reader_pid);
+            rb_get_elements(&uart0_ringbuffer, r->buffer, nbytes);
+            r->nbytes = nbytes;
+
+            m.sender_pid = reader_pid;
+            m.type = OPEN;
+            m.content.ptr = (char*)r;
+
+            msg_reply(&m, &m);
+           // DEBUG("uart0_thread: sending res=%i\n", res);
+
+            r = NULL;
+            restoreIRQ(state);
+        }
+    }
+}