core: sboot: Read kernel binary

Signed-off-by: Ian M. <ian@aptel.org>

3 files changed, 86 insertions, 0 deletions

diff --git a/core/file.c b/core/file.c
index 717e506..9ad1fd8 100644
--- a/core/file.c
+++ b/core/file.c
@@ -6,6 +6,18 @@
 #include <sboot/file.h>
 #include <sboot/fwi.h>
 
+static UINT64
+FileSize(EFI_FILE_HANDLE FileHandle)
+{
+    EFI_FILE_INFO *FileInfo;
+    UINT64 Size;
+
+    FileInfo = LibFileInfo(FileHandle);
+    Size = FileInfo->FileSize;
+    FreePool(FileInfo);
+    return Size;
+}
+
 EFI_STATUS
 FileGetVolume(IN EFI_HANDLE ImageHandle, OUT EFI_FILE_HANDLE *Handle)
 {
@@ -53,3 +65,63 @@ FileGetVolume(IN EFI_HANDLE ImageHandle, OUT EFI_FILE_HANDLE *Handle)
     *Handle = Volume;
     return EFI_SUCCESS;
 }
+
+EFI_STATUS
+FileReadToBuffer(IN CHAR16 *FileName, OUT VOID **Buffer)
+{
+    EFI_FILE_HANDLE Handle;
+    EFI_STATUS Status;
+    UINT64 ReadSize;
+    UINT8 *DataBuffer;
+
+    Status = uefi_call_wrapper(
+        gBootVolume->Open,
+        5,
+        gBootVolume,
+        &Handle,
+        FileName,
+        EFI_FILE_MODE_READ,
+        EFI_FILE_READ_ONLY | EFI_FILE_HIDDEN | EFI_FILE_SYSTEM
+    );
+
+    if (EFI_ERROR(Status)) {
+        Print(L"fatal: could not open %s\n", FileName);
+        return Status;
+    }
+
+    ReadSize = FileSize(Handle);
+    Status = uefi_call_wrapper(
+        gBS->AllocatePool,
+        3,
+        EfiLoaderData,
+        ReadSize,
+        &DataBuffer
+    );
+
+    if (EFI_ERROR(Status)) {
+        return EFI_OUT_OF_RESOURCES;
+    }
+
+    Status = uefi_call_wrapper(
+        Handle->Read,
+        3,
+        Handle,
+        &ReadSize,
+        DataBuffer
+    );
+
+    if (EFI_ERROR(Status)) {
+        Print(L"fatal: could not read %s\n", FileName);
+        FreePool(DataBuffer);
+        return Status;
+    }
+
+    uefi_call_wrapper(
+        Handle->Close,
+        1,
+        Handle
+    );
+
+    *Buffer = DataBuffer;
+    return EFI_SUCCESS;
+}
diff --git a/core/sboot.c b/core/sboot.c
index 5511ca4..604c768 100644
--- a/core/sboot.c
+++ b/core/sboot.c
@@ -10,6 +10,10 @@
 #include <sboot/fwi.h>
 #include <sboot/file.h>
 
+/* Private globals */
+static UINT8 *KernelBin = NULL;
+
+/* Globals */
 EFI_FILE_HANDLE gBootVolume;
 
 EFI_STATUS
@@ -41,5 +45,10 @@ efi_main(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     );
 
     SBootMenu(&Entry);
+    Status = FileReadToBuffer(Entry.BootPath, (VOID **)&KernelBin);
+    if (EFI_ERROR(Status)) {
+        Hcf();
+    }
+
     for (;;);
 }
diff --git a/head/sboot/file.h b/head/sboot/file.h
index cdae2bc..44e8fbb 100644
--- a/head/sboot/file.h
+++ b/head/sboot/file.h
@@ -18,4 +18,9 @@ extern EFI_FILE_HANDLE gBootVolume;
  */
 EFI_STATUS FileGetVolume(IN EFI_HANDLE ImageHandle, OUT EFI_FILE_HANDLE *Handle);
 
+/*
+ * Read a file into a buffer.
+ */
+EFI_STATUS FileReadToBuffer(IN CHAR16 *FileName, OUT VOID **Buffer);
+
 #endif  /* !_SBOOT_FILE_H_ */