multiboot: set up memory information

Author: fabianfreyer

loader.c

@@ -128,6 +128,11 @@ loader_main(struct loader_callbacks *cb, void *arg, int version, int ndisks)
             goto error;
         }
 
+        if (multiboot_info_set_meminfo(&mb->info, lowmem, highmem)) {
+            ERROR(EINVAL, "Could not set up memory information");
+            goto error;
+        }
+
         if (multiboot_info_set_cmdline(&mb->info, loader_args.cmdline)) {
             ERROR(EINVAL, "Could not set kernel command line");
             goto error;

multiboot.c

@@ -42,6 +42,16 @@
 
 void *entry = NULL;
 
+uint32_t
+multiboot_info_set_meminfo(struct multiboot_info* info,
+                           uint32_t mem_lower, uint32_t mem_upper)
+{
+    info->mem_lower = mem_lower;
+    info->mem_upper = mem_upper;
+    info->flags |= MULTIBOOT_MEMINFO;
+    return 0;
+}
+
 uint32_t
 multiboot_info_set_cmdline(struct multiboot_info* info, const char* cmdline)
 {

multiboot.h

@@ -221,6 +221,18 @@ multiboot_load_elf(void *kernel, size_t kernsz, Elf *kernel_elf);
 uint32_t
 multiboot_load(void* kernel, size_t kernsz, struct multiboot *mb);
 
+/**
+ * @brief Set the multiboot info memory information
+ *
+ * @param info pointer to the multiboot_info struct
+ * @param mem_lower the amount of lower memory starting at 0
+ * @param mem_upper the amount of upper memory starting at 1 MiB
+ * @return uint32_t 0 on success, error code on failure
+ */
+uint32_t
+multiboot_info_set_meminfo(struct multiboot_info* info,
+                           uint32_t mem_lower, uint32_t mem_upper);
+
 /**
  * @brief Set multiboot info command line
  *