Now that we understand the 32-bit assembly on Linux, making the transition to IA64 should go fairly smoothly as there is some overlap in knowledge, as we will soon see. It was an important decision to break up assembly and the ELF specification into two chapters because it's necessary to make sure you have a solid understanding of IA32 and ELF32 first before moving on to IA64 and 64-bit ELF.
Since there aren't many differences between the ELF specification on 32-bit and 64-bit, it's less important for the ELF specification to be broken up; however, the differences between IA32 and IA64 are significant, especially when we look at the general-purpose registers and making system calls in IA64. Due to this, I just kept the ELF specification with its appropriate system architecture. Go back and reread the previous chapter...