lib/efi_selftest/efi_selftest_fdt.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * efi_selftest_pos
   4  *
   5  * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
   6  *
   7  * Test the EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.
   8  *
   9  * The following services are tested:
  10  * OutputString, TestString, SetAttribute.
  11  */
  12
  13 #include <efi_selftest.h>
  14 #include <linux/libfdt.h>
  15
  16 static const struct efi_system_table *systemtab;
  17 static const struct efi_boot_services *boottime;
  18 static const char *fdt;
  19
  20 /* This should be sufficient for */
  21 #define BUFFERSIZE 0x100000
  22
  23 static const efi_guid_t fdt_guid = EFI_FDT_GUID;
  24 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
  25
  26 /*
  27  * Convert FDT value to host endianness.
  28  *
  29  * @val         FDT value
  30  * @return      converted value
  31  */
  32 static uint32_t f2h(fdt32_t val)
  33 {
  34         char *buf = (char *)&val;
  35         char i;
  36
  37 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
  38         /* Swap the bytes */
  39         i = buf[0]; buf[0] = buf[3]; buf[3] = i;
  40         i = buf[1]; buf[1] = buf[2]; buf[2] = i;
  41 #endif
  42         return *(uint32_t *)buf;
  43 }
  44
  45 /*
  46  * Return the value of a property of the FDT root node.
  47  *
  48  * @name        name of the property
  49  * @return      value of the property
  50  */
  51 static char *get_property(const u16 *property)
  52 {
  53         struct fdt_header *header = (struct fdt_header *)fdt;
  54         const fdt32_t *pos;
  55         const char *strings;
  56
  57         if (!header)
  58                 return NULL;
  59
  60         if (f2h(header->magic) != FDT_MAGIC) {
  61                 printf("Wrong magic\n");
  62                 return NULL;
  63         }
  64
  65         pos = (fdt32_t *)(fdt + f2h(header->off_dt_struct));
  66         strings = fdt + f2h(header->off_dt_strings);
  67
  68         for (;;) {
  69                 switch (f2h(pos[0])) {
  70                 case FDT_BEGIN_NODE: {
  71                         char *c = (char *)&pos[1];
  72                         size_t i;
  73
  74                         for (i = 0; c[i]; ++i)
  75                                 ;
  76                         pos = &pos[2 + (i >> 2)];
  77                         break;
  78                 }
  79                 case FDT_PROP: {
  80                         struct fdt_property *prop = (struct fdt_property *)pos;
  81                         const char *label = &strings[f2h(prop->nameoff)];
  82                         efi_status_t ret;
  83
  84                         /* Check if this is the property to be returned */
  85                         if (!efi_st_strcmp_16_8(property, label)) {
  86                                 char *str;
  87                                 efi_uintn_t len = f2h(prop->len);
  88
  89                                 if (!len)
  90                                         return NULL;
  91                                 /*
  92                                  * The string might not be 0 terminated.
  93                                  * It is safer to make a copy.
  94                                  */
  95                                 ret = boottime->allocate_pool(
  96                                         EFI_LOADER_DATA, len + 1,
  97                                         (void **)&str);
  98                                 if (ret != EFI_SUCCESS) {
  99                                         efi_st_printf("AllocatePool failed\n");
 100                                         return NULL;
 101                                 }
 102                                 boottime->copy_mem(str, &pos[3], len);
 103                                 str[len] = 0;
 104
 105                                 return str;
 106                         }
 107
 108                         pos = &pos[3 + ((f2h(prop->len) + 3) >> 2)];
 109                         break;
 110                 }
 111                 case FDT_NOP:
 112                         pos = &pos[1];
 113                         break;
 114                 default:
 115                         return NULL;
 116                 }
 117         }
 118 }
 119
 120 /**
 121  * efi_st_get_config_table() - get configuration table
 122  *
 123  * @guid:       GUID of the configuration table
 124  * Return:      pointer to configuration table or NULL
 125  */
 126 static void *efi_st_get_config_table(const efi_guid_t *guid)
 127 {
 128         size_t i;
 129
 130         for (i = 0; i < systab.nr_tables; i++) {
 131                 if (!guidcmp(guid, &systemtab->tables[i].guid))
 132                         return systemtab->tables[i].table;
 133         }
 134         return NULL;
 135 }
 136
 137 /*
 138  * Setup unit test.
 139  *
 140  * @handle:     handle of the loaded image
 141  * @systable:   system table
 142  * @return:     EFI_ST_SUCCESS for success
 143  */
 144 static int setup(const efi_handle_t img_handle,
 145                  const struct efi_system_table *systable)
 146 {
 147         void *acpi;
 148
 149         systemtab = systable;
 150         boottime = systable->boottime;
 151
 152         acpi = efi_st_get_config_table(&acpi_guid);
 153         fdt = efi_st_get_config_table(&fdt_guid);
 154
 155         if (!fdt) {
 156                 efi_st_error("Missing device tree\n");
 157                 return EFI_ST_FAILURE;
 158         }
 159         if (acpi) {
 160                 efi_st_error("Found ACPI table and device tree\n");
 161                 return EFI_ST_FAILURE;
 162         }
 163         return EFI_ST_SUCCESS;
 164 }
 165
 166 /*
 167  * Execute unit test.
 168  *
 169  * @return:     EFI_ST_SUCCESS for success
 170  */
 171 static int execute(void)
 172 {
 173         char *str;
 174         efi_status_t ret;
 175
 176         str = get_property(L"compatible");
 177         if (str) {
 178                 efi_st_printf("compatible: %s\n", str);
 179                 ret = boottime->free_pool(str);
 180                 if (ret != EFI_SUCCESS) {
 181                         efi_st_error("FreePool failed\n");
 182                         return EFI_ST_FAILURE;
 183                 }
 184         } else {
 185                 efi_st_printf("Missing property 'compatible'\n");
 186                 return EFI_ST_FAILURE;
 187         }
 188         str = get_property(L"serial-number");
 189         if (str) {
 190                 efi_st_printf("serial-number: %s\n", str);
 191                 ret = boottime->free_pool(str);
 192                 if (ret != EFI_SUCCESS) {
 193                         efi_st_error("FreePool failed\n");
 194                         return EFI_ST_FAILURE;
 195                 }
 196         }
 197
 198         return EFI_ST_SUCCESS;
 199 }
 200
 201 EFI_UNIT_TEST(fdt) = {
 202         .name = "device tree",
 203         .phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
 204         .setup = setup,
 205         .execute = execute,
 206 };