Add simulation support for Occlum embedded mode demo

demos/embedded_mode/Makefile

@@ -1,3 +1,12 @@
+SGX_SDK ?= /opt/intel/sgxsdk
+SGX_MODE ?= HW
+
+ifneq ($(SGX_MODE), HW)
+	OCCLUM_LIB := /opt/occlum/build_sim/lib
+else
+	OCCLUM_LIB := /opt/occlum/build/lib
+endif
+
 .PHONY: all build_src test clean
 
 all: occlum_context
@@ -16,7 +25,7 @@ build_src:
 
 TOTAL_BYTES := 10000000000 # 10GB
 test:
-	LD_LIBRARY_PATH=/opt/occlum/build/lib RUST_BACKTRACE=1 \
+	LD_LIBRARY_PATH=$(OCCLUM_LIB):$(SGX_SDK)/sdk_libs RUST_BACKTRACE=1 \
 		./bench_driver/build/bench_driver $(TOTAL_BYTES)
 
 clean:

demos/embedded_mode/README.md

@@ -63,3 +63,9 @@ To run the benchmark, use the following command
 ```
 make test
 ```
+
+To test in SGX simulation mode, use the following command
+```
+SGX_MODE=SIM make
+SGX_MODE=SIM make test
+```

demos/embedded_mode/bench_driver/Makefile

@@ -1,5 +1,6 @@
 SGX_SDK ?= /opt/intel/sgxsdk
 OCCLUM_PREFIX ?= /opt/occlum
+SGX_MODE ?= HW
 
 BUILD_DIR := build
 BIN := $(BUILD_DIR)/bench_driver
@@ -7,12 +8,22 @@ BIN := $(BUILD_DIR)/bench_driver
 C_SRCS := $(sort $(wildcard *.c))
 C_OBJS := $(addprefix $(BUILD_DIR)/,$(C_SRCS:.c=.o))
 
+ifneq ($(SGX_MODE), HW)
+	URTS_LIBRARY_NAME := sgx_urts_sim
+	UAE_SERVICE_LIBRARY_NAME := sgx_uae_service_sim
+	OCCLUM_BUILD := build_sim
+else
+	URTS_LIBRARY_NAME := sgx_urts
+	UAE_SERVICE_LIBRARY_NAME := sgx_uae_service
+	OCCLUM_BUILD := build
+endif
+
 C_FLAGS := -Wall \
 	-I$(SGX_SDK)/include \
 	-I$(OCCLUM_PREFIX)/include
 LINK_FLAGS := $(C_FLAGS) -lpthread \
-	-L$(SGX_SDK)/lib64 -lsgx_urts -lsgx_uprotected_fs \
-	-L$(OCCLUM_PREFIX)/build/lib -locclum-pal
+	-L$(SGX_SDK)/lib64 -l$(URTS_LIBRARY_NAME) -l$(UAE_SERVICE_LIBRARY_NAME) -lsgx_uprotected_fs \
+	-L$(OCCLUM_PREFIX)/$(OCCLUM_BUILD)/lib -locclum-pal
 
 ALL_BUILD_SUBDIRS := $(sort $(patsubst %/,%,$(dir $(BIN) $(C_OBJS))))