"Penglai" is an extensible TEE system based on RISC-V. Unlike existing systems, Penglai extends existing RISC-V hardware primitives to support scalability of isolated environments through hardware-software collaboration. In order to achieve the generality of software trust base, the Penglai architecture has designed a layer of "security primitive" interface in the security monitor and the specific hardware primitive. The management logic of trusted environment instances will be implemented on this generic interface, without caring about specific hardware isolation and protection mechanisms. Specifically, the current Penglai system implementation is based on a new RISC-V instruction set extension: the s-mode Physical Memory Protection (sPMP) mechanism, which allows scalable physical memory protection in the TEE OS or Secure monitor.In addition to the sPMP hardware extension, Penglai also supports Enclave protection via the existing physical memory isolation mechanism.