1 /*
2 * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <assert.h>
8 #include <string.h>
9
10 #include <drivers/coreboot/cbmem_console.h>
11 #include <common/debug.h>
12 #include <lib/coreboot.h>
13 #include <lib/mmio.h>
14 #include <lib/xlat_tables/xlat_tables_v2.h>
15
16 /*
17 * Structures describing coreboot's in-memory descriptor tables. See
18 * <coreboot>/src/commonlib/include/commonlib/coreboot_tables.h for
19 * canonical implementation.
20 */
21
22 typedef struct {
23 char signature[4];
24 uint32_t header_bytes;
25 uint32_t header_checksum;
26 uint32_t table_bytes;
27 uint32_t table_checksum;
28 uint32_t table_entries;
29 } cb_header_t;
30
31 typedef enum {
32 CB_TAG_MEMORY = 0x1,
33 CB_TAG_SERIAL = 0xf,
34 CB_TAG_CBMEM_CONSOLE = 0x17,
35 } cb_tag_t;
36
37 typedef struct {
38 uint32_t tag;
39 uint32_t size;
40 union {
41 coreboot_memrange_t memranges[COREBOOT_MAX_MEMRANGES];
42 coreboot_serial_t serial;
43 uint64_t uint64;
44 };
45 } cb_entry_t;
46
47 coreboot_memrange_t coreboot_memranges[COREBOOT_MAX_MEMRANGES];
48 coreboot_serial_t coreboot_serial;
49
50 /*
51 * The coreboot table is parsed before the MMU is enabled (i.e. with strongly
52 * ordered memory), so we cannot make unaligned accesses. The table entries
53 * immediately follow one another without padding, so nothing after the header
54 * is guaranteed to be naturally aligned. Therefore, we need to define safety
55 * functions that can read unaligned integers.
56 */
read_le32(uint32_t * p)57 static uint32_t read_le32(uint32_t *p)
58 {
59 uintptr_t addr = (uintptr_t)p;
60 return mmio_read_8(addr) |
61 mmio_read_8(addr + 1) << 8 |
62 mmio_read_8(addr + 2) << 16 |
63 mmio_read_8(addr + 3) << 24;
64 }
read_le64(uint64_t * p)65 static uint64_t read_le64(uint64_t *p)
66 {
67 return read_le32((void *)p) | (uint64_t)read_le32((void *)p + 4) << 32;
68 }
69
expand_and_mmap(uintptr_t baseaddr,size_t size)70 static void expand_and_mmap(uintptr_t baseaddr, size_t size)
71 {
72 uintptr_t pageaddr = round_down(baseaddr, PAGE_SIZE);
73 size_t expanded = round_up(baseaddr - pageaddr + size, PAGE_SIZE);
74 mmap_add_region(pageaddr, pageaddr, expanded,
75 MT_MEMORY | MT_RW | MT_NS | MT_EXECUTE_NEVER);
76 }
77
setup_cbmem_console(uintptr_t baseaddr)78 static void setup_cbmem_console(uintptr_t baseaddr)
79 {
80 static console_cbmc_t console;
81 assert(!console.console.base); /* should only have one CBMEM console */
82
83 /* CBMEM console structure stores its size in first header field. */
84 uint32_t size = *(uint32_t *)baseaddr;
85 expand_and_mmap(baseaddr, size);
86 console_cbmc_register(baseaddr, &console);
87 console_set_scope(&console.console, CONSOLE_FLAG_BOOT |
88 CONSOLE_FLAG_RUNTIME |
89 CONSOLE_FLAG_CRASH);
90 }
91
coreboot_get_memory_type(uintptr_t start,size_t size)92 coreboot_memory_t coreboot_get_memory_type(uintptr_t start, size_t size)
93 {
94 int i;
95
96 for (i = 0; i < COREBOOT_MAX_MEMRANGES; i++) {
97 coreboot_memrange_t *range = &coreboot_memranges[i];
98
99 if (range->type == CB_MEM_NONE)
100 break; /* end of table reached */
101 if ((start >= range->start) &&
102 (start - range->start < range->size) &&
103 (size <= range->size - (start - range->start))) {
104 return range->type;
105 }
106 }
107
108 return CB_MEM_NONE;
109 }
110
coreboot_table_setup(void * base)111 void coreboot_table_setup(void *base)
112 {
113 cb_header_t *header = base;
114 void *ptr;
115 int i;
116
117 if (strncmp(header->signature, "LBIO", 4)) {
118 ERROR("coreboot table signature corrupt!\n");
119 return;
120 }
121
122 ptr = base + header->header_bytes;
123 for (i = 0; i < header->table_entries; i++) {
124 size_t size;
125 cb_entry_t *entry = ptr;
126
127 if (ptr - base >= header->header_bytes + header->table_bytes) {
128 ERROR("coreboot table exceeds its bounds!\n");
129 break;
130 }
131
132 switch (read_le32(&entry->tag)) {
133 case CB_TAG_MEMORY:
134 size = read_le32(&entry->size) -
135 offsetof(cb_entry_t, memranges);
136 if (size > sizeof(coreboot_memranges)) {
137 ERROR("Need to truncate coreboot memranges!\n");
138 size = sizeof(coreboot_memranges);
139 }
140 memcpy(&coreboot_memranges, &entry->memranges, size);
141 break;
142 case CB_TAG_SERIAL:
143 memcpy(&coreboot_serial, &entry->serial,
144 sizeof(coreboot_serial));
145 break;
146 case CB_TAG_CBMEM_CONSOLE:
147 setup_cbmem_console(read_le64(&entry->uint64));
148 break;
149 default:
150 /* There are many tags TF doesn't need to care about. */
151 break;
152 }
153
154 ptr += read_le32(&entry->size);
155 }
156 }
157