Vol. 3D 41-1

SGX INSTRUCTION REFERENCES

CHAPTER 41

SGX INSTRUCTION REFERENCES

This chapter describes the supervisor and user level instructions provided by Intel

®

 Software Guard Extensions 

(Intel

®

 SGX). In general, a various functionality is encoded as leaf functions within the ENCLS (supervisor) and 

ENCLU (user) instruction mnemonics. Different leaf functions are encoded by specifying an input value in the EAX 
register of the respective instruction mnemonic.

41.1 

INTEL® SGX INSTRUCTION SYNTAX AND OPERATION

ENCLS and ENCLU instruction mnemonics for all leaf functions are covered in this section.
For all instructions, the value of CS.D is ignored; addresses and operands are 64 bits in 64-bit mode and are other-
wise 32 bits. Aside from EAX specifying the leaf number as input, each instruction leaf may require all or some 
subset of the RBX/RCX/RDX as input parameters. Some leaf functions may return data or status information in one 
or more of the general purpose registers.

41.1.1 

ENCLS Register Usage Summary

Table 41-1 summarizes the implicit register usage of supervisor mode enclave instructions.

41.1.2 

ENCLU Register Usage Summary

Table 41-2 Summarized the implicit register usage of user mode enclave instructions.

Table 41-1.  Register Usage of Privileged Enclave Instruction Leaf Functions

Instr. Leaf

EAX 

RBX

RCX

RDX

ECREATE

00H (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

EADD

01H (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

EINIT

02H (In)

SIGSTRUCT (In, EA)

SECS (In, EA)

EINITTOKEN (In, EA)

EREMOVE

03H (In)

EPCPAGE (In, EA)

EDBGRD

04H (In)

Result Data (Out)

EPCPAGE (In, EA)

EDBGWR

05H (In)

Source Data (In)

EPCPAGE (In, EA)

EEXTEND

06H (In)

SECS (In, EA)

EPCPAGE (In, EA)

ELDB

07H (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

VERSION (In, EA)

ELDU

08H (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

VERSION (In, EA)

EBLOCK

09H (In)

EPCPAGE (In, EA)

EPA

0AH (In)

PT_VA (In)

EPCPAGE (In, EA)

EWB

0BH (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

VERSION (In, EA)

ETRACK

0CH (In)

EPCPAGE (In, EA)

EAUG

0DH (In)

PAGEINFO (In, EA)

EPCPAGE (In, EA)

LINADDR

EMODPR

0EH (In)

SECINFO (In, EA)

EPCPAGE (In, EA)

EMODT

0FH (In)

SECINFO (In, EA)

EPCPAGE (In, EA)

EA: Effective Address