diff options
Diffstat (limited to 'arch/x86/boot/compressed/efi.c')
| -rw-r--r-- | arch/x86/boot/compressed/efi.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/efi.c b/arch/x86/boot/compressed/efi.c index 72a81ba1f87b..350838ed80db 100644 --- a/arch/x86/boot/compressed/efi.c +++ b/arch/x86/boot/compressed/efi.c @@ -77,3 +77,46 @@ unsigned long efi_get_system_table(struct boot_params *bp) return sys_tbl_pa; } + +/** + * efi_get_conf_table - Given a pointer to boot_params, locate and return the physical + * address of EFI configuration table. + * + * @bp: pointer to boot_params + * @cfg_tbl_pa: location to store physical address of config table + * @cfg_tbl_len: location to store number of config table entries + * + * Return: 0 on success. On error, return params are left unchanged. + */ +int efi_get_conf_table(struct boot_params *bp, unsigned long *cfg_tbl_pa, + unsigned int *cfg_tbl_len) +{ + unsigned long sys_tbl_pa; + enum efi_type et; + int ret; + + if (!cfg_tbl_pa || !cfg_tbl_len) + return -EINVAL; + + sys_tbl_pa = efi_get_system_table(bp); + if (!sys_tbl_pa) + return -EINVAL; + + /* Handle EFI bitness properly */ + et = efi_get_type(bp); + if (et == EFI_TYPE_64) { + efi_system_table_64_t *stbl = (efi_system_table_64_t *)sys_tbl_pa; + + *cfg_tbl_pa = stbl->tables; + *cfg_tbl_len = stbl->nr_tables; + } else if (et == EFI_TYPE_32) { + efi_system_table_32_t *stbl = (efi_system_table_32_t *)sys_tbl_pa; + + *cfg_tbl_pa = stbl->tables; + *cfg_tbl_len = stbl->nr_tables; + } else { + return -EINVAL; + } + + return 0; +} |