Massive backlog of changes

2022-06-15 15:59:31 -05:00
parent c962a83ff0
commit a52f06f81e
49 changed files with 1855 additions and 1083 deletions
--- a/src/memmap.c
+++ b/src/memmap.c
@@ -0,0 +1,136 @@
+#include "memmap.h"
+#include <stdbool.h>
+
+int compare_regions(struct memory_region_t *lhs, struct memory_region_t *rhs)
+{
+    if(lhs->location == rhs->location)
+    {
+        return lhs->size > rhs->size ? 1
+            : (lhs->size == rhs->size ? 0
+            : -1);
+    }
+    else
+    {
+        return lhs->location > rhs->location ? 1 : -1;
+    }
+}
+
+bool region_overlaps(struct memory_region_t *lhs, struct memory_region_t *rhs)
+{
+    if(rhs->location < lhs->location)
+    {
+        return rhs->location + rhs->size > lhs->location;
+    }
+    return rhs->location < lhs->location + lhs->size;
+}
+
+bool region_contains(struct memory_region_t *lhs, struct memory_region_t *rhs)
+{
+    return (rhs->location >= lhs->location) &&
+        (rhs->location + rhs->size <= lhs->location + lhs->size);
+}
+
+void insert_map_entry(struct memory_map_t *map, physaddr_t location, size_t size, unsigned int type)
+{
+    struct memory_region_t new_region = {.location = location, .size = size, .type = type};
+    unsigned int i = 0;
+    while(i < map->size)
+    {
+        if(compare_regions(&new_region, &map->array[i]) < 0)
+        {
+            struct memory_region_t buffer = new_region;
+            new_region = map->array[i];
+            map->array[i] = buffer;
+        }
+        i++;
+    }
+    map->array[i] = new_region;
+    map->size++;
+}
+
+void remove_map_entry(struct memory_map_t *map, int index)
+{
+    if(index >= 0 && index < map->size)
+    {
+        for(int i = index; i < map->size - 1; i++)
+        {
+            map->array[i] = map->array[i + 1];
+        }
+        map->size--;
+    }
+}
+
+int trim_map(struct memory_map_t *map, int index)
+{
+    if(index + 1 >= map->size)
+    {
+        return -1;
+    }
+    struct memory_region_t *left = &map->array[index];
+    struct memory_region_t *right = &map->array[index + 1];
+    if(region_overlaps(left, right))
+    {
+        if(left->type == right->type)
+        {
+            left->size = (right->location + right->size > left->location + left->size ? right->location + right->size : left->location + left->size) - left->location;
+            remove_map_entry(map, index + 1);
+            return index;
+        }
+        else if(left->type < right->type)
+        {
+            if(region_contains(right, left))
+            {
+                remove_map_entry(map, index);
+                return index;
+            }
+            else if(left->location + left->size <= right->location + right->size)
+            {
+                left->size = (right->location > left->location) ? right->location - left->location : 0;
+                return index + 1;
+            }
+            else
+            {
+                struct memory_region_t new_right = {
+                    .location = right->location + right->size, 
+                    .size = (left->location + left->size) - (right->location + right->size), 
+                    .type = left->type};
+                left->size = (right->location > left->location) ? right->location - left->location : 0;
+                if(left->size == 0)
+                    remove_map_entry(map, index);
+                insert_map_entry(map, new_right.location, new_right.size, new_right.type);
+                return index + 2;
+            }
+        }
+        else
+        {
+            if(region_contains(left, right))
+            {
+                remove_map_entry(map, index + 1);
+                return index;
+            }
+            else
+            {
+                right->size = (right->location + right->size) - (left->location + left->size);
+                right->location = left->location + left->size;
+                return index + 1;
+            }
+        }
+    }
+    else if((left->location + left->size == right->location) && left->type == right->type)
+    {
+        left->size = right->location + right->size - left->location;
+        remove_map_entry(map, index + 1);
+        return index;
+    }
+    return index + 1;
+}
+
+void insert_region(struct memory_map_t *map, physaddr_t location, size_t size, unsigned int type)
+{
+    insert_map_entry(map, location, size, type);
+    int i = 0;
+    while(i >= 0)
+    {
+        i = trim_map(map, i);
+    }
+}