Mercurial > lcfOS
comparison cos/kernel/multiboot.c @ 37:5c20bd53cccd
Cleanup
| author | windel |
|---|---|
| date | Mon, 16 Jan 2012 21:38:55 +0100 |
| parents | |
| children |
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| 36:91f91ff07ea8 | 37:5c20bd53cccd |
|---|---|
| 1 #include "kernel.h" | |
| 2 | |
| 3 multiboot_info_t *multiboot_info = 0; // Set by startup code. | |
| 4 uint64_t available_memory = 0; | |
| 5 uint64_t ramdisk_location = 0; | |
| 6 | |
| 7 /* Retrieve memory information from multiboot header */ | |
| 8 void read_multiboot_info() | |
| 9 { | |
| 10 if ((multiboot_info->flags & (1 << 6)) == (1 << 6)) | |
| 11 { | |
| 12 multiboot_memory_map_t *mmap; | |
| 13 for (mmap = (multiboot_memory_map_t*)(uint64_t)multiboot_info->mmap_addr; | |
| 14 (uint64_t)mmap < multiboot_info->mmap_addr + multiboot_info->mmap_length; | |
| 15 mmap = (multiboot_memory_map_t*) ( (uint64_t)mmap + mmap->size + sizeof(mmap->size)) ) | |
| 16 { | |
| 17 /* | |
| 18 printf("size: %d, start: 0x%x, length=0x%x, type=%d\n", mmap->size, | |
| 19 mmap->base, mmap->length, mmap->type); | |
| 20 */ | |
| 21 | |
| 22 if ( (mmap->type == 1) && (mmap->base == 0x100000) ) | |
| 23 { | |
| 24 available_memory = mmap->length; | |
| 25 } | |
| 26 } | |
| 27 } | |
| 28 | |
| 29 if (available_memory == 0) | |
| 30 { | |
| 31 panic("Found no usable memory in grub's memory map\n"); | |
| 32 } | |
| 33 | |
| 34 if ((multiboot_info->flags & (1 << 3)) == (1 << 3)) | |
| 35 { | |
| 36 uint64_t i; | |
| 37 multiboot_module_t *mod = (multiboot_module_t*)(uint64_t)multiboot_info->mods_addr; | |
| 38 for (i=0; i<multiboot_info->mods_count; i++) | |
| 39 { | |
| 40 // TODO: determine better way of finding the initrd module. | |
| 41 if (i == 0) | |
| 42 { | |
| 43 ramdisk_location = mod->mod_start; | |
| 44 } | |
| 45 | |
| 46 // Make sure that placement malloc does not overwrite the ramdisk. | |
| 47 uint64_t new_placement = (uint64_t)mod->mod_end; | |
| 48 if (new_placement > placement_address) | |
| 49 { | |
| 50 if ((new_placement & 0xFFF) != 0) | |
| 51 { | |
| 52 new_placement = (new_placement & (~0xFFF)) + 0x1000; // Align to 4 KiB page. | |
| 53 } | |
| 54 placement_address = new_placement; | |
| 55 } | |
| 56 mod++; // Go to next module. | |
| 57 } | |
| 58 } | |
| 59 } | |
| 60 |