[Trustedgrub-users] how does stage1 measure stage2

[Li R. <lir...@gm...>]

hello!
i have a question about the measurement.As we know that stage1 has only 512 byte,the former grub is nearly 512 byte,then in the Trustedgrub stage1 is added the function that it can measure stage2,but the space of the stage1 is limited,so my question is that how does stage1 measure stage2.
 Thanks!