Dir cleanup

src/fat12boot.c

@@ -0,0 +1,53 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "fat12.h"
+
+#define kPolmonAddress ((void*)0x0600)
+#define kFatAddress ((void*)0x1000)
+#define kRootDirAddress ((void*)0x1200)
+
+static int putchar(int c) {
+    register uint8_t khar asm("al") = c;
+    register uint8_t func asm("ah") = 0x0e;
+    register uint8_t page asm("bh") = 0;
+
+    asm volatile("int $0x10" ::"r"(khar), "r"(func), "r"(page) : "bp");
+
+    return c;
+}
+
+static int puts(const char* msg) {
+    while (*msg) {
+        putchar(*msg++);
+    }
+    return 0;
+}
+
+__attribute__((noreturn)) static void die(const char* msg) {
+    puts(msg);
+    while (1) {
+    }
+    __builtin_unreachable();
+}
+
+__attribute__((noreturn)) static void jump(void* addr) {
+    asm volatile("ljmp $0,%0" ::"i"(addr));
+    __builtin_unreachable();
+}
+
+__attribute__((noreturn)) static void loadpolmon() {
+    if (fat12_init(kFatAddress, kRootDirAddress)) {
+        die("fi");
+    }
+
+    while (fat12_readfile("POLIO   COM", kPolmonAddress)) {
+        asm volatile("mov $00, %%ah      \n\t"
+                     "int $0x16          \n\t" ::
+                             : "ax");
+    }
+
+    jump(kPolmonAddress);
+}
+
+int main() { loadpolmon(); }