Smp (#23)

* Fire up multiple processors

* Use IPIs to wake up secondary processors

* Much better exception information

* Modifications to show more information on fault

* WIP: Use real libstd

* Add TLS (not complete)

* Add random function, export getpid, cleanup

* Do not spin APs until new context

* Update rust

* Update rust

* Use rd/wrfsbase

* Implement TLS

* Implement compiler builtins and update rust

* Update rust

* Back to Redox libstd

* Update rust

libstd_real/compiler_builtins/src/lib.rs

@@ -0,0 +1,72 @@
+#![no_std]
+
+/// Memcpy
+///
+/// Copy N bytes of memory from one location to another.
+#[no_mangle]
+pub unsafe extern fn memcpy(dest: *mut u8, src: *const u8,
+                            n: usize) -> *mut u8 {
+    let mut i = 0;
+    while i < n {
+        *((dest as usize + i) as *mut u8) = *((src as usize + i) as *const u8);
+        i += 1;
+    }
+
+    dest
+}
+
+/// Memmove
+///
+/// Copy N bytes of memory from src to dest. The memory areas may overlap.
+#[no_mangle]
+pub unsafe extern fn memmove(dest: *mut u8, src: *const u8,
+                             n: usize) -> *mut u8 {
+    if src < dest as *const u8 {
+        let mut i = n;
+        while i != 0 {
+            i -= 1;
+            *((dest as usize + i) as *mut u8) = *((src as usize + i) as *const u8);
+        }
+    } else {
+        let mut i = 0;
+        while i < n {
+            *((dest as usize + i) as *mut u8) = *((src as usize + i) as *const u8);
+            i += 1;
+        }
+    }
+
+    dest
+}
+
+/// Memset
+///
+/// Fill a block of memory with a specified value.
+#[no_mangle]
+pub unsafe extern fn memset(dest: *mut u8, c: i32, n: usize) -> *mut u8 {
+    let mut i = 0;
+    while i < n {
+        *((dest as usize + i) as *mut u8) = c as u8;
+        i += 1;
+    }
+
+    dest
+}
+
+/// Memcmp
+///
+/// Compare two blocks of memory.
+#[no_mangle]
+pub unsafe extern fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
+    let mut i = 0;
+
+    while i < n {
+        let a = *((s1 as usize + i) as *const u8);
+        let b = *((s2 as usize + i) as *const u8);
+        if a != b {
+            return a as i32 - b as i32
+        }
+        i += 1;
+    }
+
+    0
+}