Replace bios with bootloader, don't use bootsector

Instead of using the bootsector to load a bootloader, just put the
bootloader in the ROM and call it a day. It looks for a file on the SD
card in the root directory named `kernel.bin` and loads it into memory.

This is not a perfect solution, as the kernel will grow larger and the
kernel load address will have to change. At this point I could add back
the bootloader, but that is for later.

Also the bootloader is just a copy of the kernel, so that can be trimmed
down a lot.

sw/bootloader/filesystem/o65.c

@@ -0,0 +1,28 @@
+#include <conio.h>
+
+#include "o65.h"
+
+void o65_print_option(o65_opt_t* opt) {
+    int i;
+
+    cprintf("Option Length: %d\n", opt->olen);
+    cprintf("Option Type: %x ", opt->type);
+
+    switch (opt->type) {
+        case O65_OPT_FILENAME: cprintf("Filename\n"); break;
+        case O65_OPT_OS: cprintf("OS\n"); break;
+        case O65_OPT_ASSEMBLER: cprintf("Assembler\n"); break;
+        case O65_OPT_AUTHOR: cprintf("Author\n"); break;
+        case O65_OPT_DATE: cprintf("Creation Date\n"); break;
+        default: cprintf("Invalid\n"); break;
+    }
+
+    if (opt->type != O65_OPT_OS) {
+        for (i = 0; i < opt->olen - 2; i++) {
+            cprintf("%c", opt->data[i]);
+        }
+    } else {
+        cprintf("%x", opt->data[0]);
+    }
+    cprintf("\n\n");
+}