Can't call system open(), read(), etc.

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@315 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/arch/sim/src/up_tapdev.c

@@ -70,6 +70,8 @@
 # define DEVTAP "/dev/tap0"
 #endif /* linux */
 
+extern int lib_rawprintf(const char *format, ...);
+
 /****************************************************************************
  * Private Definitions
  ****************************************************************************/
@@ -81,6 +83,12 @@
 #define UIP_DRIPADDR2   0
 #define UIP_DRIPADDR3   1
 
+#define READ   3
+#define WRITE  4
+#define OPEN   5
+#define IOCTL  54
+#define SELECT 82
+
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -94,14 +102,81 @@
  ****************************************************************************/
 
 #ifdef TAPDEV_DEBUG
-static int drop = 0;
+static int gdrop = 0;
 #endif
-static int fd;
+static int gtapdevfd;
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
+/* This is REALLY awkward.. we need to compile using the system header files,
+ * but we can't use any of the libc calls because all of the symbols are
+ * defined for NuttX (read, write, etc)!  So we do hand rolled syscalls
+ * to get to the Linux functions.
+ */
+
+static inline int up_open(const char *filename, int flags, int mode)
+{
+  int result;
+
+  __asm__ volatile ("int $0x80" \
+                    : "=a" (result) \
+                    : "0" (OPEN), "b" ((int)(filename)), "c" ((int)(flags)), "d" ((int)(mode)) \
+                    : "memory");
+
+  return (int)result;
+}
+
+static inline int up_read(int fd, void* buf, size_t count)
+{
+  ssize_t result;
+
+  __asm__ volatile ("int $0x80" \
+                    : "=a" (result) \
+                    : "0" (READ), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
+                    : "memory");
+
+  return (int)result;
+}
+
+static inline int up_write(int fd, const void* buf, size_t count)
+{
+  ssize_t result;
+
+  __asm__ volatile ("int $0x80" \
+                    : "=a" (result) \
+                    : "0" (WRITE), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
+                    : "memory");
+
+  return (int)result;
+}
+
+static inline int up_ioctl(int fd, unsigned int cmd, unsigned long arg)
+{
+  ssize_t result;
+
+  __asm__ volatile ("int $0x80" \
+                    : "=a" (result) \
+                    : "0" (IOCTL), "b" ((int)(fd)), "c" ((int)(cmd)), "d" ((long)(arg)) \
+                    : "memory");
+
+  return (int)result;
+}
+
+static inline int up_select(int n, fd_set *inp, fd_set *outp, fd_set *exp, struct timeval *tvp)
+{
+  ssize_t result;
+
+  __asm__ volatile ("int $0x80" \
+                    : "=a" (result) \
+                    : "0" (SELECT),"b" ((long)(n)),"c" ((long)(inp)), \
+                      "d" ((long)(outp)),"S" ((long)(exp)), "D"((long)tvp) \
+                    : "memory");
+
+  return (int)result;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -117,10 +192,10 @@ void tapdev_init(void)
 {
   char buf[1024];
 
-  fd = open(DEVTAP, O_RDWR);
-  if(fd == -1)
+  gtapdevfd = up_open(DEVTAP, O_RDWR, 0644);
+  if(gtapdevfd == -1)
     {
-      printf("tapdev: tapdev_init: open");
+      lib_rawprintf("tapdev: tapdev_init: open");
       return;
     }
 
@@ -129,16 +204,16 @@ void tapdev_init(void)
     struct ifreq ifr;
     memset(&ifr, 0, sizeof(ifr));
     ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
-    if (ioctl(fd, TUNSETIFF, (void *) &ifr) < 0)
+    if (up_ioctl(gtapdevfd, TUNSETIFF, (void *) &ifr) < 0)
       {
-        printf(buf);
+        lib_rawprintf(buf);
         return;
       }
   }
 #endif /* Linux */
 
-  snprintf(buf, sizeof(buf), "ifconfig tap0 inet %d.%d.%d.%d",
-	   UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3);
+  lib_rawprintf(buf, sizeof(buf), "ifconfig tap0 inet %d.%d.%d.%d",
+         UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3);
   system(buf);
 }
 
@@ -152,29 +227,29 @@ unsigned int tapdev_read(char *buf, unsigned int buflen)
   tv.tv_usec = 1000;
 
   FD_ZERO(&fdset);
-  FD_SET(fd, &fdset);
+  FD_SET(gtapdevfd, &fdset);
 
-  ret = select(fd + 1, &fdset, NULL, NULL, &tv);
+  ret = up_select(gtapdevfd + 1, &fdset, NULL, NULL, &tv);
   if(ret == 0)
     {
       return 0;
     }
 
-  ret = read(fd, buf, buflen);
+  ret = up_read(gtapdevfd, buf, buflen);
   if(ret == -1)
     {
-      printf("tap_dev: tapdev_read: read");
+      lib_rawprintf("tap_dev: tapdev_read: read");
     }
 
 #ifdef TAPDEV_DEBUG
-  printf("tap_dev: tapdev_read: read %d bytes\n", ret);
+  lib_rawprintf("tap_dev: tapdev_read: read %d bytes\n", ret);
   {
     int i;
     for(i = 0; i < 20; i++)
       {
-        printf("%x ", buf[i]);
+        lib_rawprintf("%x ", buf[i]);
       }
-    printf("\n");
+    lib_rawprintf("\n");
   }
 #endif
 
@@ -185,17 +260,17 @@ void tapdev_send(char *buf, unsigned int buflen)
 {
   int ret;
 #ifdef TAPDEV_DEBUG
-  printf("tapdev_send: sending %d bytes\n", buflen);
+  lib_rawprintf("tapdev_send: sending %d bytes\n", buflen);
 
-  drop++;
-  if(drop % 8 == 7)
+  gdrop++;
+  if(gdrop % 8 == 7)
     {
-      printf("Dropped a packet!\n");
+      lib_rawprintf("Dropped a packet!\n");
       return;
     }
 #endif
 
-  ret = write(fd, buf, buflen);
+  ret = up_write(gtapdevfd, buf, buflen);
   if(ret == -1)
     {
       perror("tap_dev: tapdev_send: write");