Where is grub stage1.5 code located in the disk?

Question

I am trying to write a stage1 bootloader that will load GRUB stage1.5. So where is its code located exactly? And how can I know how big it is (so I know how many bytes I need to read) ?

Answer 1

Answer to your question is right here: http://en.wikipedia.org/wiki/GNU_GRUB#Boot_process (for both GRUB1 and GRUB2 bootloaders).