Requesting the BIOS' memory map

Qcommon.c

@@ -40,12 +40,23 @@ void serial_write(const char *msg)
 }
 
 extern void bios_write(const char *msg, unsigned length);
+extern void *bios_getmap(void *buffer);
+
+unsigned char memmap[24 * 128];
 
 void
 main()
 {
 	bios_write("init\r\n", 6);
+	void *end = bios_getmap(memmap);
 	bios_write("karlos\r\n", 8);
+	for (int i = 0; ; i++) {
+		unsigned char *entry = memmap + 24 * i;
+		if (entry >= end) break;
+		unsigned char type = *(entry + 16);
+		char c = type < 10 ? type + '0' : '?';
+		bios_write(&c, 1);
+	}
 	for (;;) {
 		__asm__ ("hlt" :);
 	}

Rnbp.S

@@ -1,4 +1,4 @@
-            // vim: et:sw=12:ts=12:sts=12
+            // vim: ft=gas:et:sw=12:ts=12:sts=12
 
             .global     _start
 
@@ -13,6 +13,7 @@
             .code32
             mov         $SS_DATA16, %ax
             mov         %ax, %ds
+            mov         %ax, %es
             mov         %ax, %ss
             ljmp        $SS_CODE16, $9f
 9:          .code16
@@ -22,6 +23,7 @@
             .code16
             mov         $SS_DATA32, %ax
             mov         %ax, %ds
+            mov         %ax, %es
             mov         %ax, %ss
             ljmp        $SS_CODE32, $9f
 9:          .code32
@@ -164,6 +166,45 @@ bios_write: push        %ebp
             pop         %ebp
             ret
 
+            .global     bios_getmap
+            .code32
+bios_getmap:push        %ebp
+            mov         %esp, %ebp
+            push        %ebx
+            push        %edi
+
+            mov         8+0(%ebp), %edi
+
+            PROT16
+            .code16
+            REAL
+
+            xor         %ebx, %ebx
+_gmnext:    movl        $0, 20(%di)
+            mov         $0x534D4150, %edx // e820 magic number
+            mov         $24, %ecx
+            mov         $0xE820, %eax
+            int         $0x15
+            jc          _gmdone
+            test        %ebx, %ebx
+            jz          _gmdone
+            add         $24, %di
+            jmp         _gmnext
+_gmdone:    add         $24, %di
+
+
+            PROT
+            PROT32
+            .code32
+
+            mov         %edi, %eax
+            
+            pop         %edi
+            pop         %ebx
+            mov         %ebp, %esp
+            pop         %ebp
+            ret
+
             .data
 
 real_ss:    .word       0