Merge pull request #35 from Ghifari160/master

Fix typos and 404's

12-kernel-c/README.md

@@ -37,7 +37,7 @@ generates machine code without any labels and/or metadata
 
 *Note: a warning may appear when linking, disregard it*
 
-Now examine both "binary" files, `function.o` and `function.bin` using `xdd`. You
+Now examine both "binary" files, `function.o` and `function.bin` using `xxd`. You
 will see that the `.bin` file is machine code, while the `.o` file has a lot
 of debugging information, labels, etc.
 

14-checkpoint/README.md

@@ -20,7 +20,7 @@ on Homebrew's repos)
 
 ```sh
 cd /tmp/src
-curl -O http://ftp.rediris.es/mirror/GNU/gnu/gdb/gdb-7.8.tar.gz
+curl -O http://ftp.rediris.es/mirror/GNU/gdb/gdb-7.8.tar.gz
 tar xf gdb-7.8.tar.gz
 mkdir gdb-build
 cd gdb-build