More Fixes

example/guest/src/example.c

@@ -3,13 +3,21 @@
 
 #include <trampoline/types.h>
 
+// Error-Checking
+static void safe_trampoline(const uint32_t id, uint32_t *ret, const uint32_t length, const unsigned char *args) {
+    const uint32_t err = raw_trampoline(id, ret, length, args);
+    if (err != 0) {
+        fprintf(stderr, "Error: %u\n", err);
+    }
+}
+
 // Call Trampoline With String
-void run(uint32_t cmd, const char *str) {
+void run(const uint32_t cmd, const char *str) {
-    unsigned char *args = (unsigned char *) str;
+    const unsigned char *args = (const unsigned char *) str;
     // Send Command
     fprintf(stderr, "Guest Is Sending: %u: %s\n", cmd, str);
     uint32_t ret;
-    raw_trampoline(cmd, &ret, strlen(str) + 1, args);
+    safe_trampoline(cmd, &ret, strlen(str) + 1, args);
     fprintf(stderr, "Guest Has Received: %u\n", ret);
 }
 
@@ -25,6 +33,6 @@ int main() {
     // Calls without a return value *may* return control
     // to guest code before the call has finished.
     INFO("Testing Trampoline Call That May Return Early");
-    raw_trampoline(100, NULL, 0, NULL);
+    safe_trampoline(100, NULL, 0, NULL);
     fprintf(stderr, "Control Returned To Guest\n");
 }

example/host/src/trampoline.c

@@ -7,8 +7,8 @@
 // writer: Function That Can Write To Guest Memory
 // id: Command ID
 // args: Pointer To Command Arguments
-// Return Value: Returned To The Guest (Unless Early Return Is Enabled)
+// Return Value: Returned To The Guest
-uint32_t trampoline(trampoline_writer_t writer, uint32_t id, const unsigned char *args) {
+uint32_t trampoline(trampoline_writer_t writer, const uint32_t id, const unsigned char *args) {
     if (id == 100 /* Defined In ../../guest/src/example.c */) {
         // Early Return Allowed
         fprintf(stderr, "Early Return Call Started\n");

scripts/install-dependencies-ARM64.sh

@@ -10,4 +10,4 @@ apt-get install -y --no-install-recommends \
     ninja-build \
     gcc g++ \
     gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf \
-    libc6:armhf
+    libc6:armhf libstdc++6:armhf