Re: [U-Boot] [PATCH 3/4] efi_loader: implement ConvertPointer()

On Sat, Jul 27, 2019 at 11:00:03PM +0200, Heinrich Schuchardt wrote:

Implement the ConvertPointer() runtime service.

I already submitted a similar patch: https://lists.denx.de/pipermail/u-boot/2019-June/371773.html

Anyhow,

Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de

lib/efi_loader/efi_runtime.c | 75 ++++++++++++++++++++++++++++++++++-- 1 file changed, 71 insertions(+), 4 deletions(-)

diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index a8f0b5eae3..2286e847a7 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -81,6 +81,10 @@ struct elf_rela { long addend; };

+static __efi_runtime_data struct efi_mem_desc *efi_virtmap; +static __efi_runtime_data efi_uintn_t efi_descriptor_count; +static __efi_runtime_data efi_uintn_t efi_descriptor_size;

/*

• EFI runtime code lives in two stages. In the first stage, U-Boot and an EFI
• payload are running concurrently at the same time. In this mode, we can

@@ -89,7 +93,9 @@ struct elf_rela {

efi_status_t efi_init_runtime_supported(void) {

• u16 efi_runtime_services_supported = 0;

• u16 efi_runtime_services_supported =

• 		EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP ||
  

"||" -> "|"

• 		EFI_RT_SUPPORTED_CONVERT_POINTER;
  
  

  /*

  • This value must be synced with efi_runtime_detach_list

@@ -98,8 +104,7 @@ efi_status_t efi_init_runtime_supported(void) #ifdef CONFIG_EFI_HAVE_RUNTIME_RESET efi_runtime_services_supported |= EFI_RT_SUPPORTED_RESET_SYSTEM; #endif

• efi_runtime_services_supported |=

• 		EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP;
  

• return EFI_CALL(efi_set_variable(L"RuntimeServicesSupported", &efi_global_variable_guid, EFI_VARIABLE_BOOTSERVICE_ACCESS |

@@ -454,6 +459,58 @@ static __efi_runtime efi_status_t EFIAPI efi_convert_pointer_runtime( return EFI_UNSUPPORTED; }

+/**

• • efi_convert_pointer_runtime() - convert from physical to virtual pointer
• • This function implements the ConvertPointer() runtime service until
• • the first call to SetVirtualAddressMap().
• • See the Unified Extensible Firmware Interface (UEFI) specification for
• • details.
• • @debug_disposition: indicates if pointer may be converted to NULL
• • @address: pointer to be converted
• • Return: status code EFI_UNSUPPORTED
• */

+static __efi_runtime efi_status_t EFIAPI efi_convert_pointer(

• 	efi_uintn_t debug_disposition, void **address)
  

+{

• efi_physical_addr_t addr = (uintptr_t)*address;
• efi_uintn_t i;
• efi_status_t ret = EFI_NOT_FOUND;
• EFI_ENTRY("%zu %p", debug_disposition, address);
• if (!efi_virtmap) {

• ret = EFI_UNSUPPORTED;
  

• goto out;
  

• }
• if (!address) {

• ret = EFI_INVALID_PARAMETER;
  

• goto out;
  

• }
• for (i = 0; i < efi_descriptor_count; i++) {

• struct efi_mem_desc *map = (void *)efi_virtmap +
  

• 			   (efi_descriptor_size * i);
  

• if (addr >= map->physical_start &&
  

•     (addr < map->physical_start
  

• 	    + (map->num_pages << EFI_PAGE_SHIFT))) {
  

• 	*address = (void *)(uintptr_t)
  

• 		   (addr + map->virtual_start -
  

• 		    map->physical_start);
  

• 	ret = EFI_SUCCESS;
  

• 	break;
  

• }
  

• }

+out:

• return EFI_EXIT(ret);

+}

static __efi_runtime void efi_relocate_runtime_table(ulong offset) { ulong patchoff; @@ -480,6 +537,12 @@ static __efi_runtime void efi_relocate_runtime_table(ulong offset) */ efi_runtime_services.convert_pointer = &efi_convert_pointer_runtime;

• /*

• * TODO: Update UEFI variable RuntimeServicesSupported removing flags
  

• * EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP and
  

• * EFI_RT_SUPPORTED_CONVERT_POINTER as required by the UEFI spec 2.8.
  

• */
  

• /* Update CRC32 */ efi_update_table_header_crc32(&efi_runtime_services.hdr);

} @@ -584,6 +647,10 @@ static efi_status_t EFIAPI efi_set_virtual_address_map( EFI_ENTRY("%zx %zx %x %p", memory_map_size, descriptor_size, descriptor_version, virtmap);

• efi_virtmap = virtmap;
• efi_descriptor_size = descriptor_size;
• efi_descriptor_count = n;

As I mentioned in the patch above,

! /* Rebind mmio pointers */ ! for (i = 0; i < n; i++) { ! ...

This part of code in efi_set_virtual_address_map() is fragile as entries in efi_runtime_mmio belong to memory allocated by calloc(), which means that they are no longer accessible at runtime.

-Takahiro Akashi

/* * TODO: * Further down we are cheating. While really we should implement @@ -800,7 +867,7 @@ struct efi_runtime_services __efi_runtime_data efi_runtime_services = { .get_wakeup_time = (void *)&efi_unimplemented, .set_wakeup_time = (void *)&efi_unimplemented, .set_virtual_address_map = &efi_set_virtual_address_map,

• .convert_pointer = (void *)&efi_unimplemented,

• .convert_pointer = efi_convert_pointer, .get_variable = efi_get_variable, .get_next_variable_name = efi_get_next_variable_name, .set_variable = efi_set_variable,

-- 2.20.1