diff options
Diffstat (limited to 'qemu/roms/seabios/src/e820map.c')
| -rw-r--r-- | qemu/roms/seabios/src/e820map.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/qemu/roms/seabios/src/e820map.c b/qemu/roms/seabios/src/e820map.c new file mode 100644 index 000000000..39445cf63 --- /dev/null +++ b/qemu/roms/seabios/src/e820map.c @@ -0,0 +1,152 @@ +// Support for building memory maps suitable for int 15 e820 calls. +// +// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net> +// +// This file may be distributed under the terms of the GNU LGPLv3 license. + +#include "config.h" // BUILD_MAX_E820 +#include "e820map.h" // struct e820entry +#include "output.h" // dprintf +#include "string.h" // memmove + + +/**************************************************************** + * e820 memory map + ****************************************************************/ + +// Info on e820 map location and size. +struct e820entry e820_list[BUILD_MAX_E820] VARFSEG; +int e820_count VARFSEG; + +// 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 >= BUILD_MAX_E820) { + warn_noalloc(); + 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; +} + +static const char * +e820_type_name(u32 type) +{ + switch (type) { + case E820_RAM: return "RAM"; + case E820_RESERVED: return "RESERVED"; + case E820_ACPI: return "ACPI"; + case E820_NVS: return "NVS"; + case E820_UNUSABLE: return "UNUSABLE"; + default: return "UNKNOWN"; + } +} + +// Show the current e820_list. +static void +dump_map(void) +{ + 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: %016llx - %016llx = %d %s\n", i + , e->start, e_end, e->type, e820_type_name(e->type)); + } +} + +#define E820_HOLE ((u32)-1) // Used internally to remove entries + +// Add a new entry to the list. This scans for overlaps and keeps the +// list sorted. +void +e820_add(u64 start, u64 size, u32 type) +{ + dprintf(8, "Add to e820 map: %08llx %08llx %d\n", start, size, type); + + if (! size) + // Huh? Nothing to do. + return; + + // Find position of new item (splitting existing item if needed). + u64 end = start + size; + int i; + for (i=0; i<e820_count; i++) { + struct e820entry *e = &e820_list[i]; + u64 e_end = e->start + e->size; + if (start > e_end) + continue; + // Found position - check if an existing item needs to be split. + if (start > e->start) { + if (type == e->type) { + // Same type - merge them. + size += start - e->start; + start = e->start; + } else { + // Split existing item. + e->size = start - e->start; + i++; + if (e_end > end) + insert_e820(i, end, e_end - end, e->type); + } + } + break; + } + // Remove/adjust existing items that are overlapping. + while (i<e820_count) { + struct e820entry *e = &e820_list[i]; + if (end < e->start) + // No overlap - done. + break; + u64 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 - end; + if (type == e->type) { + // Same type - merge them. + size += e->size; + remove_e820(i); + } + break; + } + // Insert new item. + if (type != E820_HOLE) + insert_e820(i, start, size, type); + //dump_map(); +} + +// Remove any definitions in a memory range (make a memory hole). +void +e820_remove(u64 start, u64 size) +{ + e820_add(start, size, E820_HOLE); +} + +// Report on final memory locations. +void +e820_prepboot(void) +{ + dump_map(); +} |