syscalls: implement basic execve syscall, no argc, argv, envp support yet

grubshit/callee.c

@@ -0,0 +1,22 @@
+// callee.c
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[], char *envp[]) {
+    printf("--- In callee.c ---\n");
+    printf("This program has taken over the process.\n");
+
+    printf("argc: %d\n", argc);
+
+    printf("\nArguments (argv):\n");
+    for (int i = 0; argv[i] != NULL; i++) {
+        printf("  argv[%d]: %s\n", i, argv[i]);
+    }
+
+    printf("\nEnvironment Variables (envp):\n");
+    for (int i = 0; envp[i] != NULL; i++) {
+        printf("  %s\n", envp[i]);
+    }
+
+    return 0;
+}

grubshit/caller.c

@@ -0,0 +1,26 @@
+// caller.c
+#include <stdio.h>
+#include <unistd.h>
+
+int main() {
+    printf("--- In caller.c ---\n");
+    printf("This message is from the original program.\n");
+    printf("Calling execve to run './callee'...\n\n");
+
+    // Arguments for the new program
+    // The first argument is conventionally the program name
+    char *argv[] = {NULL}; //{ "./callee", "first_arg", "second_arg", NULL };
+
+    // Environment variables for the new program
+    char *envp[] = {NULL}; //{ "CUSTOM_VAR=Hello from caller!", "ANOTHER_VAR=123", NULL };
+
+    // The execve system call
+    // The first argument is the path to the executable
+    // The second is the array of arguments
+    // The third is the array of environment variables
+    execve("callee.", argv, envp);
+
+    // This part of the code will only be reached if execve fails
+    perror("execve failed");
+    return 1;
+}