kern: syscall: Add initial write(2) stub

Here we add a write(2) stub and add it to the UNIX syscall interface. We
also move the UNIX syscall numbers into compat/unix/syscall.h

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/sys/os/os_filedes.c b/src/sys/os/os_filedes.c
new file mode 100644
index 0000000..ecb94ef
--- /dev/null
+++ b/src/sys/os/os_filedes.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/syscall.h>
+#include <sys/syslog.h>
+#include <sys/errno.h>
+#include <os/filedesc.h>
+#include <io/cons/cons.h>
+#include <sys/proc.h>
+#include <string.h>
+
+#define STDOUT_FILENO 1
+
+/*
+ * XXX: STUB
+ */
+ssize_t
+write(int fd, const void *buf, size_t count)
+{
+    int error;
+    char kbuf[1024];
+
+    /* Must be valid */
+    error = proc_check_addr(proc_self(), (uintptr_t)buf, count);
+    if (error < 0) {
+        return error;
+    }
+
+    memcpy(kbuf, buf, count);
+
+    switch (fd) {
+    case STDOUT_FILENO:
+        cons_putstr(
+            &g_root_scr, kbuf,
+            count
+        );
+        break;
+    default:
+        return -EBADF;
+    }
+
+    return count;
+}