[lib][uefi][debug_support]: re-factoring debug support code.

We modify the debug support code to support directly given the path.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>

Author: grandpaul

lib/uefi/debug_support.cpp

@@ -25,6 +25,7 @@
 #include <uefi/protocols/loaded_image_protocol.h>
 #include <uefi/types.h>
 
+#include "charset.h"
 #include "uefi_platform.h"
 
 struct EFI_DEVICE_PATH_FILE_PATH_PROTOCOL {
@@ -197,7 +198,7 @@ void efi_core_remove_debug_image_info_entry(EfiHandle image_handle)
 EfiStatus setup_debug_support(EfiSystemTable &table,
 			      char *image_base,
 			      size_t virtual_size,
-			      bdev_t *dev) {
+			      const char *dev_name) {
   EfiLoadedImageProtocol *efiLoadedImageProtocol = nullptr;
 
   allocate_pool(EFI_MEMORY_TYPE_BOOT_SERVICES_DATA,
@@ -210,7 +211,11 @@ EfiStatus setup_debug_support(EfiSystemTable &table,
   efiLoadedImageProtocol->image_base = reinterpret_cast<void *>(image_base);
   efiLoadedImageProtocol->image_size = virtual_size;
   char *device_buf = nullptr;
-  size_t fpsize = sizeof(EfiDevicePathProtocol) + 2 * (strlen(dev->name) + 2);
+  /* fpsize is the size of the struct that EfiDevicePathProtocol stores the
+     dev_name. And dev_name will be converted to UTF-16, and ended by null
+     character. So the size is the length of dev_name plus one, and multiply
+     by 2 */
+  size_t fpsize = sizeof(EfiDevicePathProtocol) + 2 * (strlen(dev_name) + 1);
   allocate_pool(EFI_MEMORY_TYPE_BOOT_SERVICES_DATA,
 		fpsize + sizeof(EfiDevicePathProtocol),
 		reinterpret_cast<void **>(&device_buf));
@@ -221,10 +226,7 @@ EfiStatus setup_debug_support(EfiSystemTable &table,
   fp->dp.sub_type = EFI_DEVICE_PATH_SUB_TYPE_FILE_PATH;
   fp->dp.length[0] = fpsize % 256;
   fp->dp.length[1] = fpsize / 256;
-  fp->str[0] = '\\';
-  for (size_t i = 0; i < strlen(dev->name); i++) {
-    fp->str[i+1] = dev->name[i];
-  }
+  utf8_to_utf16(reinterpret_cast<char16_t *>(&fp->str), dev_name, strlen(dev_name) + 1);
   dp_end->type = EFI_DEVICE_PATH_TYPE_END;
   dp_end->sub_type = EFI_DEVICE_PATH_SUB_TYPE_END;
   dp_end->length[0] = sizeof(EfiDevicePathProtocol) % 256;

lib/uefi/debug_support.h

@@ -65,7 +65,7 @@ void efi_core_remove_debug_image_info_entry(EfiHandle image_handle);
 EfiStatus setup_debug_support(EfiSystemTable &table,
 			      char *image_base,
 			      size_t virtual_size,
-			      bdev_t *dev);
+			      const char *dev_name);
 
 void teardown_debug_support(char *image_base);