There is quite a bit of confusion in the EFI code as to whether a field contains an address or a pointer. As a first step towards resolving this, document the memory-descriptor struct, indicating that it holds pointers, not addresses.
Dro the same for efi_add_memory_map() as it is widely used, as well as efi_add_memory_map_pg() which is only used by lmb
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: - Adjust comments
Changes in v2: - Fix missing @ - Note that this holds pointers, not addresses
include/efi.h | 21 +++++++++++++++++++++ include/efi_loader.h | 6 ++++-- lib/efi_loader/efi_memory.c | 4 +++- 3 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/include/efi.h b/include/efi.h index c559fda3004..348ff9efd16 100644 --- a/include/efi.h +++ b/include/efi.h @@ -273,6 +273,27 @@ enum efi_memory_type { #define EFI_PAGE_SIZE (1ULL << EFI_PAGE_SHIFT) #define EFI_PAGE_MASK (EFI_PAGE_SIZE - 1)
+/** + * struct efi_mem_desc - defines an EFI memory record + * + * This field implements the EFI_MEMORY_DESCRIPTOR type of the UEFI + * specification. + * + * Note that this struct is for use outside U-Boot, so the two 'start' fields + * are pointers, not addresses. Use map_to_sysmem() to convert to an address, so + * that sandbox operates correctly. + * + * @type (enum efi_memory_type): EFI memory-type + * @reserved: unused + * @physical_start: Start address of region in physical memory + * @virtual_start: Start address of region in virtual memory, which will be the + * same as @physical_start before where both addresses will always be the + * same before SetVirtualMemoryMap() is called as the UEFI specification + * requires identity mapping. + * @num_pages: Number of EFI pages this record covers (each is EFI_PAGE_SIZE + * bytes) + * @attribute: Memory attributes (see EFI_MEMORY_...) + */ struct efi_mem_desc { u32 type; u32 reserved; diff --git a/include/efi_loader.h b/include/efi_loader.h index 39809eac1bc..ee0cdd36500 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -788,8 +788,10 @@ efi_status_t efi_add_memory_map(u64 start, u64 size, int memory_type); /** * efi_add_memory_map_pg() - add pages to the memory map * - * @start: start address, must be a multiple of - * EFI_PAGE_SIZE + * @start: start address, must be a multiple of EFI_PAGE_SIZE. Note that this + * is actually a pointer provided as an integer. To pass in an address, pass + * in (ulong)map_to_sysmem(addr) + * * @pages: number of pages to add * @memory_type: type of memory added * @overlap_conventional: region may only overlap free(conventional) diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c index e493934c713..f1154f73e05 100644 --- a/lib/efi_loader/efi_memory.c +++ b/lib/efi_loader/efi_memory.c @@ -384,7 +384,9 @@ efi_status_t efi_add_memory_map_pg(u64 start, u64 pages, /** * efi_add_memory_map() - add memory area to the memory map * - * @start: start address of the memory area + * @start: start address of the memory area. Note that this is + * actually a pointer provided as an integer. To pass in + * an address, pass in (ulong)map_to_sysmem(addr) * @size: length in bytes of the memory area * @memory_type: type of memory added *