blob: 1cc4691f24f7b730092789ab2185d424cf80900c [file] [log] [blame]
// Support for building memory maps suitable for int 15 e820 calls.
//
// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "memmap.h" // struct e820entry
#include "util.h" // dprintf.h
#include "biosvar.h" // SET_EBDA
// Remove an entry from the e820_list.
static void
remove_e820(int i)
{
e820_count--;
memmove(&e820_list[i], &e820_list[i+1]
, sizeof(e820_list[0]) * (e820_count - i));
}
// Insert an entry in the e820_list at the given position.
static void
insert_e820(int i, u64 start, u64 size, u32 type)
{
if (e820_count >= CONFIG_MAX_E820) {
dprintf(1, "Overflowed e820 list!\n");
return;
}
memmove(&e820_list[i+1], &e820_list[i]
, sizeof(e820_list[0]) * (e820_count - i));
e820_count++;
struct e820entry *e = &e820_list[i];
e->start = start;
e->size = size;
e->type = type;
}
// Show the current e820_list.
static void
dump_map()
{
dprintf(1, "e820 map has %d items:\n", e820_count);
int i;
for (i=0; i<e820_count; i++) {
struct e820entry *e = &e820_list[i];
u64 e_end = e->start + e->size;
dprintf(1, " %d: %x%x - %x%x = %d\n", i
, (u32)(e->start >> 32), (u32)e->start
, (u32)(e_end >> 32), (u32)e_end
, e->type);
}
}
// Add a new entry to the list. This scans for overlaps and keeps the
// list sorted.
void
add_e820(u64 start, u64 size, u32 type)
{
dprintf(8, "Add to e820 map: %x %x %d\n", (u32)start, (u32)size, type);
if (! size)
// Huh? Nothing to do.
return;
u64 end = start + size;
int i;
for (i=0; i<e820_count; i++) {
struct e820entry *e = &e820_list[i];
if (end < e->start)
// Simple insertion point.
break;
u64 e_end = e->start + e->size;
if (start > e_end)
// No overlap.
continue;
// New item overlaps (or borders) an existing one.
if (start > e->start) {
e->size = start - e->start;
i++;
if (end < e_end)
// Need to split existing item
insert_e820(i, end, e_end - end, e->type);
if (type == e->type) {
// Same type - merge them.
size += start - e->start;
start = e->start;
i--;
remove_e820(i);
}
}
if (type != E820_HOLE) {
insert_e820(i, start, size, type);
i++;
}
// Remove all existing items that are completely overlapped.
while (i<e820_count) {
e = &e820_list[i];
if (end < e->start)
// No overlap - done.
break;
e_end = e->start + e->size;
if (end >= e_end) {
// Existing item completely overlapped - remove it.
remove_e820(i);
continue;
}
// Not completely overlapped - adjust its start.
e->start = end;
e->size = e_end - e->start;
if (type == e->type) {
// Same type - merge them.
(e-1)->size += e->size;
remove_e820(i);
}
break;
}
//dump_map();
return;
}
// Just insert item.
insert_e820(i, start, size, type);
//dump_map();
}
// Prep for memmap stuff - init bios table locations.
void
memmap_setup()
{
bios_table_cur_addr = (u32)BiosTableSpace;
bios_table_end_addr = bios_table_cur_addr + CONFIG_MAX_BIOSTABLE;
dprintf(1, "bios_table_addr: 0x%08x end=0x%08x\n",
bios_table_cur_addr, bios_table_end_addr);
e820_count = 0;
}
// Report on final memory locations.
void
memmap_finalize()
{
dump_map();
dprintf(1, "final bios_table_addr: 0x%08x (used %d%%)\n"
, bios_table_cur_addr
, (100 * (bios_table_cur_addr - (u32)&BiosTableSpace)
/ CONFIG_MAX_BIOSTABLE));
if (bios_table_cur_addr > bios_table_end_addr)
panic("bios_table_end_addr overflow!\n");
}