1 files changed, 182 insertions, 0 deletions
diff --git a/include/unistd.h b/include/unistd.h
new file mode 100644
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--- /dev/null
+++ b/include/unistd.h
@@ -0,0 +1,182 @@
+/**
+ * @file unistd.h
+ * @author Freya Murphy <freya@freyacat.org>
+ * @author Warren R. Carithers
+ *
+ * Universial system definitions for userspace.
+ */
+
+#ifndef _UNISTD_H
+#define _UNISTD_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+/* System Call Definitions */
+
+typedef uint_t pid_t;
+
+/**
+ * Terminates the calling process and does not return.
+ * @param status - the status code to exit with
+ */
+__attribute__((noreturn)) extern void exit(int32_t status);
+
+/**
+ * Sleeps current process until a child process terminates
+ *
+ * @param pid - pid of the desired child, or 0 for any child
+ * @param status - Pointer to int32_t into which the child's status is placed,
+ *                 or NULL
+ *
+ * @return The pid of the terminated child, or an error code
+ *
+ * If there are no children in the system, returns an error code (*status
+ * is unchanged).
+ *
+ * If there are one or more children in the system and at least one has
+ * terminated but hasn't yet been cleaned up, cleans up that process and
+ * returns its information; otherwise, blocks until a child terminates.
+ */
+extern int waitpid(pid_t pid, int32_t *status);
+
+/**
+ * Create a duplicate of the calling process
+ *
+ * @return   parent - the pid of the new child, or an error code
+ *           child  - 0
+ */
+extern int fork(void);
+
+/**
+ * Replace the memory image of the calling process
+ *
+ * @param prog - program table index of the program to exec
+ * @param args - the command-line argument vector
+ *
+ * Does not return if it succeeds; if it returns, something has
+ * gone wrong.
+ */
+extern void exec(uint_t prog, char **args);
+
+/**
+ * Open a stream with a given filename
+ *
+ * @param filename - the name of the file to open
+ * @return the file descriptior of the open file or a negative error code.
+ * TODO: fmurphy implement
+ */
+extern int open(char *filename);
+
+/**
+ * Closes a stream with the given file descriptior
+ * @param fd - the file descriptior of the open stream
+ * TODO: fmurphy implement
+ */
+extern void close(int fd);
+
+/**
+ * Read into a buffer from a stream
+ *
+ * @param fd - file stream to read from
+ * @param buf - buffer to read into
+ * @param nbytes - maximum capacity of the buffer
+ *
+ * @return - The count of bytes transferred, or an error code
+ * TODO: fmurphy FD
+ */
+extern int read(int fd, void *buffer, size_t nbytes);
+
+/**
+ * Write from a buffer to a stream
+ *
+ * @param fd - file stream to write to
+ * @param buf - buffer to write from
+ * @param nbytes - maximum capacity of the buffer
+ *
+ * @return - The count of bytes transferred, or an error code
+ * TODO: fmurphy FD
+ */
+extern int write(int fd, const void *buffer, size_t nbytes);
+
+/**
+ * Gets the pid of the calling process
+ *
+ * @return the pid of this process
+ */
+extern pid_t getpid(void);
+
+/**
+ * Gets the parent pid of the current process
+ *
+ * @return the parent pid of the current process, or 0 if init
+ */
+extern pid_t getppid(void);
+
+/**
+ * Gets the current system time
+ *
+ * @return the system time
+ * TODO: CHANGE TIME TO 64bits!!
+ */
+extern ulong_t gettime(void);
+
+/**
+ * Gets the scheduling priority of the calling process
+ *
+ * @return the process' priority
+ */
+extern uint_t getprio(void);
+
+/**
+ * Sets the scheduling priority of the calling process
+ *
+ * @param new - the desired new priority
+ *
+ * @return the old priority value
+ */
+extern uint_t setprio(uint_t new);
+
+/**
+ * Terminates a process
+ *
+ * @param pid - the pid of the process to kill
+ *
+ * @return 0 on success, else an error code
+ */
+extern int32_t kill(pid_t pid);
+
+/**
+ * Put the current process to sleep for some length of time
+ *
+ * @param ms - desired sleep time (in ms), or 0 to yield the CPU
+ *
+ * @return the time the process spent sleeping (in ms)
+ */
+extern int sleep(uint32_t ms);
+
+/**
+ * Wait for any child to exit
+ *
+ * @param status - Pointer to int32_t into which the child's status is placed,
+ *                 or NULL
+ *
+ * @return  The pid of the terminated child, or an error code
+ *
+ * Analogous to waitpid(0,status)
+ */
+extern int wait(int32_t *status);
+
+/**
+ * Spawn a new process running a different program
+ *
+ * @param prog - program table index of the program to spawn
+ * @param args - the command-line argument vector for the process
+ *
+ * @return      The pid of the child, or an error code
+ *
+ * Analogous to calling fork and exec
+ */
+extern int spawn(uint_t prog, char **args);
+
+#endif /* unistd.h */