This answer is the culmination of everything the fine folks in the comments have said. First of all the gdt should be made up of 64 bit entries, not 16 bit. Second of all the limit should be placed in the struct for the gdtr before the base. To make the code safer I switched the "r" with a "m" in the inline asm and passed a value into the gdtr. Thank you all again for the comments and support!