Fix build scripts, align some code, make a workable test

build.sh

@@ -10,6 +10,7 @@ clang -fPIC -nostdlib -I "include" -g "src/ciabatta.c" -c -o "bin/ciabatta.o"
 rm "$LIB_FILE" 2> /dev/null
 
 if [ "$1" != "-shared" ]; then
+    [ -f "lib/ciabatta.a" ] && rm "lib/ciabatta.a"
     llvm-ar -q "lib/ciabatta.a" "bin/crt_ctors.o" "bin/crt_entry.o" "bin/ciabatta.o"
 else
     clang -fPIC -nostdlib -shared -o "lib/ciabatta.so" "bin/ciabatta.o"

src/linux/crt_entry.asm

@@ -24,7 +24,7 @@ _start:
     pop rsi
     mov rdx, qword [rsp]
     ;; Align stack to 16, push junk and stack ptr
-    and rsi, ~0xf
+    and rsp, ~0xf
     push rax
     push rsp
     ;; Push fini and init sections

src/linux/entry.c

@@ -1,4 +1,10 @@
 
+
+int __stack_chk_fial() {
+    // TODO: implement proper stack protector support
+    return 0;
+}
+
 void __libc_start_main(
     int (*main)(int, char**, char**),
     int argc, char **argv,
@@ -7,5 +13,7 @@ void __libc_start_main(
     void (*rtld_fini)(void),
     void *stack_end
 ) {
+    static char string[] = "Hello, world!\n";
+    syscall_write(STDOUT_FILENO, string, sizeof string);
     syscall_exit(0);
 }

src/linux/syscall.c

@@ -1,6 +1,10 @@
 
 #if os_is_linux()
 
+#define STDIN_FILENO  0
+#define STDOUT_FILENO 1
+#define STDERR_FILENO 2
+
 #define SYS_read           0
 #define SYS_write          1
 #define SYS_open           2