From ffb09e4938021ed47bc7097585dd19a10f2e09de Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Tue, 27 Jan 2015 14:04:30 -0500
Subject: [PATCH 3/5] EFI/early: Implement GetNextVariableName and /query and
 /noexitboot parameters

In the early EFI boot we will enumerate up to five EFI variables
to make sure it works.

The /query will just enumerate them and then quit. Helps in
troubleshooting and redirecting the output to a file (xen.efi /query > q).

The /noexitboot will inhibit Xen from calling ExitBootServices.
This allows on Lenovo ThinkPad x230 to use GetNextVariableName
in 1-1 mapping mode.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 xen/common/efi/boot.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index b0bbc4b..4ee8f68 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -673,6 +673,74 @@ static void __init setup_efi_pci(void)
     efi_bs->FreePool(handles);
 }
 
+static int __init efi_getnextvariable(bool_t query_only)
+{
+    EFI_GUID guid;
+    UINTN i, size, idx;
+    CHAR16 *name;
+    EFI_STATUS status;
+
+
+    status = efi_bs->AllocatePool(EfiLoaderData, 1024, (void *)&name);
+    if ( EFI_ERROR(status) )
+        return status;
+
+    guid.Data1 = 0;
+    guid.Data2 = 0;
+    guid.Data3 = 0;
+    for ( i = 0; i < 8; i++ )
+        guid.Data4[i] = 0;
+
+    for ( i = 0 ; i < 1024 / sizeof (CHAR16); i++ )
+        name[i] = 0;
+
+    PrintStr(L"GetNextVariableName: ");
+    PrintStr(name);
+    PrintStr(newline);
+    idx = 0;
+    do {
+        size = 1024;
+        efi_rs->GetNextVariableName(&size, name, &guid);
+        if ( EFI_ERROR(status) )
+        {
+            if ( query_only )
+            {
+                efi_bs->FreePool(name);
+                PrintErrMesg(L"Failed to GetNextVariableName", status);
+            }
+            else
+            {
+                PrintStr(L"Warning: GetNextVariableName: ");
+                DisplayUint(status, 0);
+                PrintStr(newline);
+            }
+        }
+        else
+        {
+            DisplayUint(guid.Data1, 4);
+            DisplayUint(guid.Data2, 2);
+            DisplayUint(guid.Data3, 2);
+            for ( i = 0; i < 8; i++ )
+                DisplayUint(guid.Data4[i], 1);
+
+            PrintStr(L":");
+            PrintStr(name);
+            PrintStr(L" ");
+            DisplayUint(status, 0);
+            PrintStr(newline);
+        }
+    } while ( !EFI_ERROR(status) && idx++ < 5 );
+
+    efi_bs->FreePool(name);
+
+    if ( query_only )
+        return -EINVAL;
+
+    if ( EFI_ERROR(EFI_NOT_FOUND) )
+        return 0;
+
+    return status;
+}
 static int __init __maybe_unused set_color(u32 mask, int bpp, u8 *pos, u8 *sz)
 {
    if ( bpp < 0 )
@@ -705,8 +773,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *mode_info;
     union string section = { NULL }, name;
     bool_t base_video = 0, retry;
+    bool_t query_only = 0;
     char *option_str;
     bool_t use_cfg_file;
+    bool_t exit_boot_services = 0;
 
     efi_ih = ImageHandle;
     efi_bs = SystemTable->BootServices;
@@ -751,6 +821,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
             {
                 if ( wstrcmp(ptr + 1, L"basevideo") == 0 )
                     base_video = 1;
+                else if ( wstrcmp(ptr + 1, L"query") == 0 )
+                    query_only = 1;
+                else if ( wstrcmp(ptr + 1, L"noexitboot") == 0 )
+                    exit_boot_services = 0;
                 else if ( wstrncmp(ptr + 1, L"cfg=", 4) == 0 )
                     cfg_file_name = ptr + 5;
                 else if ( i + 1 < argc && wstrcmp(ptr + 1, L"cfg") == 0 )
@@ -1031,6 +1105,9 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
         PrintStr(newline);
     }
 
+    if ( efi_getnextvariable(query_only) )
+       blexit(L"Could not get next variable");
+
     efi_arch_memory_setup();
 
     if ( gop )
@@ -1064,7 +1141,11 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 
         efi_arch_pre_exit_boot();
 
-        status = efi_bs->ExitBootServices(ImageHandle, map_key);
+        if ( exit_boot_services )
+            status = efi_bs->ExitBootServices(ImageHandle, map_key);
+        else
+            status = 0;
+
         if ( status != EFI_INVALID_PARAMETER || retry )
             break;
     }
-- 
2.1.0