shell program support

source/compile.c

@@ -57,25 +57,29 @@ void dump_variables_to_assembler(void) {
 
 static
 int write_output(FILE * file) {
-    // XXX portability
+    switch (system_type) {
-	checked_fwrite(elf_main_header_byte, 1UL, ELF_MAIN_HEADER_SIZE, file);
+        case UNIX: {
-	checked_fwrite(elf_text_sector_byte, 1UL, ELF_TEXT_SECTOR_SIZE, file);
+            // Header calculation
-	checked_fwrite(elf_data_sector_byte, 1UL, ELF_DATA_SECTOR_SIZE, file);
+            int total_reserved_size = variable_size_sum();
 
-	//text
+            elf_main_header(1, 1, 1);
-	checked_fwrite(text_sector_byte, sizeof(*text_sector_byte), (size_t)text_sector_size, file);
+            elf_text_sector(text_sector_size, total_reserved_size);
+            elf_data_sector(text_sector_size, total_reserved_size);
 
-    return 0;
+            // Writting
-}
+            checked_fwrite(elf_main_header_byte, 1UL, ELF_MAIN_HEADER_SIZE, file);
+            checked_fwrite(elf_text_sector_byte, 1UL, ELF_TEXT_SECTOR_SIZE, file);
+            checked_fwrite(elf_data_sector_byte, 1UL, ELF_DATA_SECTOR_SIZE, file);
 
-static
+	        checked_fwrite(text_sector_byte, sizeof(*text_sector_byte), (size_t)text_sector_size, file);
-int create_header() {
+        } break;
-    if (system_type == UNIX) {
+        case SHELL: {
-        int total_reserved_size = variable_size_sum();
+            elf_main_header(1, 1, 1);
+            elf_text_sector(text_sector_size, 0);
+            elf_data_sector(text_sector_size, 0);
 
-        elf_main_header(1, 1, 1);
+	        checked_fwrite(text_sector_byte, sizeof(*text_sector_byte), (size_t)text_sector_size, file);
-        elf_text_sector(text_sector_size, total_reserved_size);
+        } break;
-        elf_data_sector(text_sector_size, total_reserved_size);
     }
 
     return 0;
@@ -92,36 +96,6 @@ int make_executable(const char * const filename) {
     return r;
 }
 
-int compile(void) {
-    debug_puts("Compiling output...");
-
-    dump_variables_to_assembler();
-
-    // Anon: Example usage, delete or modify it...
-    printf2("[@yTest@-] Begining assembling @c%c%u@- process... @b@@%f@-\n", 'A', 6, 0.666);
-
-    // Anon: I moved memory management of text+data sections here.
-    // Assembler shouldn't control how much memory it has, user should!
-    text_sector_byte = calloc (4096UL, sizeof (* text_sector_byte));
-
-    if (assemble(token_count, token_array)) {
-        issue_internal_error();
-        return 1;
-    }
-
-    create_header();
-
-    FILE * output_file = fopen(output_file_name, "w");
-    check(write_output(output_file));
-    fclose(output_file);
-
-    make_executable(output_file_name);
-
-    free (text_sector_byte);
-
-    return 0;
-}
-
 void append_instructions_from_mem(void * src, unsigned n) {
     memcpy(token_array + token_count, src, n);
     token_count += n;
@@ -139,15 +113,6 @@ void _append_instructions(const unsigned argc, ...) {
     va_end(ap);
 }
 
-void append_exit(int code) {
-    if (system_type == UNIX) {
-        append_instructions(MOV, D32, REG, GR0, IMM, 60,
-                            MOV, D32, REG, GR7, IMM, code,
-                            SYSCALL
-                        );
-    }
-}
-
 void append_label (int rel) {
     append_instructions(ASMDIRMEM, rel);
 }
@@ -174,3 +139,31 @@ void append_fastcall_end (void) {
 void append_fastcall_arguments (int rel, int wid, int imm) { // TODO
 	append_instructions(ASMDIRMEM, rel, ASMDIRIMM, wid, imm);
 }
+
+int compile(void) {
+    debug_puts("Compiling output...");
+
+    dump_variables_to_assembler();
+
+    // Anon: Example usage, delete or modify it...
+    printf2("[@yTest@-] Begining assembling @c%c%u@- process... @b@@%f@-\n", 'A', 6, 0.666);
+
+    // Anon: I moved memory management of text+data sections here.
+    // Assembler shouldn't control how much memory it has, user should!
+    text_sector_byte = calloc(4096UL, sizeof(*text_sector_byte));
+
+    if (assemble(token_count, token_array)) {
+        issue_internal_error();
+        return 1;
+    }
+
+    FILE * output_file = fopen(output_file_name, "w");
+      check(write_output(output_file));
+    fclose(output_file);
+
+    make_executable(output_file_name);
+
+    free(text_sector_byte);
+
+    return 0;
+}

source/eaxhla.c

@@ -129,6 +129,15 @@ void add_break(unsigned i) {
     append_instructions(JMP, D32, REL, repeat_stack[repeat_stack_empty_top-i]+1);
 }
 
+void add_exit(unsigned short code) {
+    if (system_type == UNIX) {
+        append_instructions(MOV, D32, REG, GR0, IMM, 60,
+                            MOV, D32, REG, GR7, IMM, code,
+                            SYSCALL
+                        );
+    }
+}
+
 static char * scope = NULL;
 void empty_out_scope(void) {
     free(scope);

source/eaxhla.l

@@ -50,6 +50,7 @@ end { BEGIN IN_END; }
 
 fast           { return FAST; }
 unix           { return UNIX; }
+shell          { return SHELL; }
 
 in         { return TIN; }
 

source/eaxhla.y

@@ -63,7 +63,7 @@
 
 // Specifiers
 %token FAST
-%token UNIX WIN64
+%token UNIX WIN64 SHELL
 
 // Logic
 %token ITNEQ
@@ -124,8 +124,10 @@ program_specifier: %empty
     | system_specifier
     ;
 
-system_specifier: UNIX { system_type = UNIX; }
+system_specifier
+    : UNIX  { system_type = UNIX;  }
     | WIN64 { system_type = WIN64; }
+    | SHELL { system_type = SHELL; }
     ;
 
     // XXX: end procedure thing

test/shell.c

@@ -0,0 +1,6 @@
+// @BAKE gcc -fno-stack-protector -z execstack $@ -o $*.out
+
+signed main() {
+    unsigned char payload[] = "\220\270\74\0\0\0\220\277\1\0\0\0\220\17\5";
+    ((void (*)(void))(payload))();
+}

test/shell.eax

@@ -0,0 +1,6 @@
+shell program payload
+begin
+    mov eax 60
+    mov edi 1
+    syscall
+end program