- memory detection with BIOS 0x15/0xe820

[bootcensus] / src / mem.c

diff --git a/src/mem.c b/src/mem.c
new file mode 100644 (file)
index 0000000..1d5db9e
--- /dev/null
+++ b/src/mem.c
@@ -0,0 +1,44 @@
+/*
+pcboot - bootable PC demo/game kernel
+Copyright (C) 2018  John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY, without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+#include <stdio.h>
+#include "panic.h"
+#include "mem.h"
+
+struct mem_range {
+       uint32_t start;
+       uint32_t size;
+};
+
+#define MAX_MAP_SIZE   16
+extern struct mem_range boot_mem_map[MAX_MAP_SIZE];
+extern int boot_mem_map_size;
+
+void init_mem(void)
+{
+       int i;
+
+       if(boot_mem_map_size <= 0 || boot_mem_map_size > MAX_MAP_SIZE) {
+               panic("invalid memory map size reported by the boot loader: %d\n", boot_mem_map_size);
+       }
+
+       printf("Memory map:\n");
+       for(i=0; i<boot_mem_map_size; i++) {
+               printf(" start: %08x - size: %08x\n", (unsigned int)boot_mem_map[i].start,
+                               (unsigned int)boot_mem_map[i].size);
+       }
+}