diff options
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/efi-stub-helper.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c index 1bf439be9138..a168dd20511f 100644 --- a/drivers/firmware/efi/efi-stub-helper.c +++ b/drivers/firmware/efi/efi-stub-helper.c @@ -11,6 +11,10 @@ */ #define EFI_READ_CHUNK_SIZE (1024 * 1024) +/* error code which can't be mistaken for valid address */ +#define EFI_ERROR (~0UL) + + struct file_info { efi_file_handle_t *handle; u64 size; @@ -83,6 +87,32 @@ fail: return status; } + +static unsigned long __init get_dram_base(efi_system_table_t *sys_table_arg) +{ + efi_status_t status; + unsigned long map_size; + unsigned long membase = EFI_ERROR; + struct efi_memory_map map; + efi_memory_desc_t *md; + + status = efi_get_memory_map(sys_table_arg, (efi_memory_desc_t **)&map.map, + &map_size, &map.desc_size, NULL, NULL); + if (status != EFI_SUCCESS) + return membase; + + map.map_end = map.map + map_size; + + for_each_efi_memory_desc(&map, md) + if (md->attribute & EFI_MEMORY_WB) + if (membase > md->phys_addr) + membase = md->phys_addr; + + efi_call_early(free_pool, map.map); + + return membase; +} + /* * Allocate at the highest possible address that is not above 'max'. */ |