diff --git a/port/moonlight/src/bootup.c b/port/moonlight/src/bootup.c
index 17ac817..5230ffb 100644
--- a/port/moonlight/src/bootup.c
+++ b/port/moonlight/src/bootup.c
@@ -37,6 +37,7 @@ EXTERN_C function_t __init_array_start;
 EXTERN_C function_t __init_array_end;
 EXTERN_C function_t __fini_array_start;
 EXTERN_C function_t __fini_array_end;
+EXTERN_C volatile uintptr_t tohost;
 
 // This function will be placed by the linker script according to the section
 // Raw function 'called' by the CPU with no runtime.
@@ -119,9 +120,11 @@ void _initialize(void) {
     _exit(rc);
 }
 
-// This should never be called. Busy loop with the CPU in idle state.
+// This should never be called. Report the exit code through HTIF and idle the CPU.
 void _exit(int exit_code) {
-    (void)exit_code;
+    uintptr_t htif_exit_code = (((uintptr_t)(unsigned int)exit_code) << 1) | 1u;
+
+    tohost = htif_exit_code;
     csr_clr_bits_mie(MIE_MTI_BIT_MASK);
     csr_clr_bits_mstatus(MSTATUS_MIE_BIT_MASK);
     while (1) {
diff --git a/test/threadx/CMakeLists.txt b/test/threadx/CMakeLists.txt
index 724ddc2..2eb06c7 100644
--- a/test/threadx/CMakeLists.txt
+++ b/test/threadx/CMakeLists.txt
@@ -140,26 +140,14 @@ function(add_threadx_regression_test TEST_SOURCE)
     list(APPEND TX_REGRESSION_TARGETS ${TEST_NAME})
     set(TX_REGRESSION_TARGETS ${TX_REGRESSION_TARGETS} PARENT_SCOPE)
 
-    if(TEST_NAME STREQUAL "threadx_initialize_kernel_setup_test")
-        add_test(
-            NAME ${TEST_NAME}
-            COMMAND ${CMAKE_CURRENT_LIST_DIR}/run_threadx_simple_test.sh
-            ${THREADX_TEST_SIMULATOR}
-            ${THREADX_TEST_ISA}
-            $<TARGET_FILE:${TEST_NAME}>
-            "Running Initialize Kernel Setup Test................................ SUCCESS!"
-            "Running Initialize Kernel Setup Test................................ ERROR!"
-        )
-    else()
-        add_test(
-            NAME ${TEST_NAME}
-            COMMAND ${CMAKE_CURRENT_LIST_DIR}/run_threadx_test.sh
-            ${THREADX_TEST_SIMULATOR}
-            ${THREADX_TEST_ISA}
-            $<TARGET_FILE:${TEST_NAME}>
-        )
-    endif()
-    set_tests_properties(${TEST_NAME} PROPERTIES TIMEOUT 10)
+    add_test(
+        NAME ${TEST_NAME}
+        COMMAND ${THREADX_TEST_SIMULATOR}
+        --isa=${THREADX_TEST_ISA}
+        -f $<TARGET_FILE:${TEST_NAME}>
+        -m 60s
+    )
+    set_tests_properties(${TEST_NAME} PROPERTIES TIMEOUT 60)
 endfunction()
 
 foreach(test_case ${TX_REGRESSION_CASES})
diff --git a/test/threadx/run_threadx_simple_test.sh b/test/threadx/run_threadx_simple_test.sh
deleted file mode 100755
index 1e9ef7c..0000000
--- a/test/threadx/run_threadx_simple_test.sh
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-simulator="$1"
-isa="$2"
-elf="$3"
-pass_pattern="$4"
-fail_pattern="$5"
-
-if [ ! -x "$simulator" ]; then
-    echo "Simulator not found or not executable: $simulator" >&2
-    exit 2
-fi
-
-if [ ! -f "$elf" ]; then
-    echo "ELF not found: $elf" >&2
-    exit 2
-fi
-
-log_file=$(mktemp)
-trap 'rm -f "$log_file"' EXIT
-
-"$simulator" \
-    --isa="$isa" \
-    -f "$elf" \
-    -p tb.top.core.finish_condition=1 \
-    -m 10s \
-    | tee "$log_file"
-
-if grep -Fq "$fail_pattern" "$log_file"; then
-    echo "ThreadX regression reported failure pattern: $fail_pattern" >&2
-    exit 1
-fi
-
-if ! grep -Fq "$pass_pattern" "$log_file"; then
-    echo "Missing expected success pattern in simulator output: $pass_pattern" >&2
-    exit 1
-fi
-
-exit 0
diff --git a/test/threadx/run_threadx_test.sh b/test/threadx/run_threadx_test.sh
deleted file mode 100755
index fa40c93..0000000
--- a/test/threadx/run_threadx_test.sh
+++ /dev/null
@@ -1,47 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-simulator="$1"
-isa="$2"
-elf="$3"
-
-if [ ! -x "$simulator" ]; then
-    echo "Simulator not found or not executable: $simulator" >&2
-    exit 2
-fi
-
-if [ ! -f "$elf" ]; then
-    echo "ELF not found: $elf" >&2
-    exit 2
-fi
-
-log_file=$(mktemp)
-trap 'rm -f "$log_file"' EXIT
-
-"$simulator" \
-    --isa="$isa" \
-    -f "$elf" \
-    -m 10s \
-    | tee "$log_file"
-
-summary_line=$(grep -F "**** Test Summary:" "$log_file" | tail -n 1 || true)
-if [ -z "$summary_line" ]; then
-    echo "Missing ThreadX test summary in simulator output" >&2
-    exit 1
-fi
-
-read -r passed failed errors <<EOF_SUMMARY
-$(echo "$summary_line" | sed -n 's/.*Tests Passed:[[:space:]]*\([0-9][0-9]*\)[[:space:]]*Tests Failed:[[:space:]]*\([0-9][0-9]*\)[[:space:]]*System Errors:[[:space:]]*\([0-9][0-9]*\).*/\1 \2 \3/p')
-EOF_SUMMARY
-
-if [ -z "${passed:-}" ] || [ -z "${failed:-}" ] || [ -z "${errors:-}" ]; then
-    echo "Could not parse ThreadX test summary: $summary_line" >&2
-    exit 1
-fi
-
-if [ "$failed" -ne 0 ] || [ "$errors" -ne 0 ]; then
-    echo "ThreadX regression reported failure: passed=$passed failed=$failed errors=$errors" >&2
-    exit 1
-fi
-
-exit 0