xref: /openbmc/u-boot/arch/x86/lib/e820.c (revision 4c0411eb)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
4  */
5 
6 #include <common.h>
7 #include <efi_loader.h>
8 #include <asm/e820.h>
9 
10 DECLARE_GLOBAL_DATA_PTR;
11 
12 /*
13  * Install a default e820 table with 4 entries as follows:
14  *
15  *	0x000000-0x0a0000	Useable RAM
16  *	0x0a0000-0x100000	Reserved for ISA
17  *	0x100000-gd->ram_size	Useable RAM
18  *	CONFIG_PCIE_ECAM_BASE	PCIe ECAM
19  */
20 __weak unsigned int install_e820_map(unsigned int max_entries,
21 				     struct e820_entry *entries)
22 {
23 	entries[0].addr = 0;
24 	entries[0].size = ISA_START_ADDRESS;
25 	entries[0].type = E820_RAM;
26 	entries[1].addr = ISA_START_ADDRESS;
27 	entries[1].size = ISA_END_ADDRESS - ISA_START_ADDRESS;
28 	entries[1].type = E820_RESERVED;
29 	entries[2].addr = ISA_END_ADDRESS;
30 	entries[2].size = gd->ram_size - ISA_END_ADDRESS;
31 	entries[2].type = E820_RAM;
32 	entries[3].addr = CONFIG_PCIE_ECAM_BASE;
33 	entries[3].size = CONFIG_PCIE_ECAM_SIZE;
34 	entries[3].type = E820_RESERVED;
35 
36 	return 4;
37 }
38 
39 #if CONFIG_IS_ENABLED(EFI_LOADER)
40 void efi_add_known_memory(void)
41 {
42 	struct e820_entry e820[E820MAX];
43 	unsigned int i, num;
44 	u64 start, pages;
45 	int type;
46 
47 	num = install_e820_map(ARRAY_SIZE(e820), e820);
48 
49 	for (i = 0; i < num; ++i) {
50 		start = e820[i].addr;
51 		pages = ALIGN(e820[i].size, EFI_PAGE_SIZE) >> EFI_PAGE_SHIFT;
52 
53 		switch (e820[i].type) {
54 		case E820_RAM:
55 			type = EFI_CONVENTIONAL_MEMORY;
56 			break;
57 		case E820_RESERVED:
58 			type = EFI_RESERVED_MEMORY_TYPE;
59 			break;
60 		case E820_ACPI:
61 			type = EFI_ACPI_RECLAIM_MEMORY;
62 			break;
63 		case E820_NVS:
64 			type = EFI_ACPI_MEMORY_NVS;
65 			break;
66 		case E820_UNUSABLE:
67 		default:
68 			type = EFI_UNUSABLE_MEMORY;
69 			break;
70 		}
71 
72 		efi_add_memory_map(start, pages, type, false);
73 	}
74 }
75 #endif /* CONFIG_IS_ENABLED(EFI_LOADER) */
76