smap-query.patch

diff --git a/boot/load.c b/boot/load.c
index f80808c..05d583a 100644
--- a/boot/load.c
+++ b/boot/load.c
@@ -1,10 +1,9 @@
+#include "memory.h"
 #include "printf.h"
 #include "modes.h"
 #include "vga.h"
 
-void test(void);
-
-__attribute__ ((naked)) void main() {
+void main() {
   __asm__ volatile(
     "movw $0x10, %%ax\n\t"
     "movw %%ax, %%ss\n\t"
@@ -17,11 +16,51 @@ __attribute__ ((naked)) void main() {
     : "ax"
   );
 
-  vga_puts("testing string formatting\n");
+  vga_puts("Starting!\n");
+
+  short int *ss = 0;
+  __asm__ (
+      "movl %%ss, %%eax\n\t"
+      "movl %%eax, %0\n\t"
+      : "=rm" (ss)
+      : /* no inputs */
+      : "ax"
+  );
+
+  unsigned int *esp = 0;
+  __asm__ (
+      "movl %%esp, %0\n\t"
+      : "=rm" (esp)
+      : /* no inputs */
+  );
+
+  unsigned int ebp = 0;
+  __asm__ (
+      "movl %%ebp, %0\n\t"
+      : "=rm" (ebp)
+      : /* no inputs */
+  );
+
+  char *fmt = (
+    "Boot Entry:   0x%x\n"
+    "Loader Entry: 0x%x\n"
+    "ss:           0x%x\n"
+    "esp:          0x%x\n"
+    "ebp:          0x%x\n"
+  );
+
+  char buf[200];
+  vsprintf(buf, 200, fmt, 0x7C00, 0x7E00, ss, esp, ebp);
+  vga_puts(buf);
+
+  uint32_t map_entry = 0;
+  map_entry = smap_get_entry(&map_entry, sizeof(map_entry));
 
-  test();
+  char map_entry_msg[100];
+  vsprintf(map_entry_msg, 100, "map: %x", map_entry);
+  vga_puts(map_entry_msg);
 
-  vga_puts("Success!");
+  vga_puts("Done!");
 
   __asm__ volatile(
     "hlt"
@@ -31,8 +70,51 @@ __attribute__ ((naked)) void main() {
   );
 }
 
-void test() {
-  char buf[40];
-  vsprintf(buf, 40, "0x%x\n", 254);
-  vga_puts(buf);
-}
+uint32_t smap_get_entry(uint32_t *entry, uint32_t size) {
+  if(entry == 0 || entry <= 0xFFFF) {
+    return 0;
+  }
+
+  if(size < 24) {
+    return 0;
+  }
+
+  /* Hexadecimal representation of the string "SMAP" */
+  uint32_t signature = 0x534D4150; 
+  uint32_t segment = entry >> 4;
+  uint32_t offset = entry - segment;
+  uint32_t prev_entry = *entry;
+
+  uint16_t es = 0;
+  __asm__ volatile(
+    "mov %%es, %0\n\t"
+    : "=rm" (es)
+  );
+
+  enter_virtual_8086_mode();
+
+  __asm__ volatile(
+    "movl %0, %%eax\n\t"
+    "movl %%eax, %%es\n\t"
+
+    "movl 0xe820, %%eax\n\t"
+    "movw %1, %%di\n\t"
+    "movl %2, %%edx\n\t"
+    "movl %3, %%ebx\n\t"
+
+    "int $0x15\n\t"
+    : /* no outputs */
+    : (segment), (offset), (signature)
+    : "eax", "ebx", "di"
+  );
+
+  exit_virtual_8086_mode();
+
+  __asm__(
+    "mov %0, %%es\n\t"
+    : /* no outputs */
+    : (es)
+  );
+
+  return 0;
+}
\ No newline at end of file