What's difference of Agilex GSRD and boot linux?


I’m trying to bring up Agilex evm board and I found out 2 documents
One is Agilex SoC GSRD(URL), the other one is Agilex SoC boot linux(URL)

These indicate bsp build step differently each other.
But I don’t know essential difference of them.

Besides, I don’t know which one is right to Agilex evm board.

Please, let me know…