OvmfPkg: QemuBootOrderLib: featurize PCI-like device path translation

In preparation for adding OpenFirmware-to-UEFI translation for "MMIO-like"
OFW device path fragments, let's turn the currently exclusive "PCI-like"
translation into "just one" of the possible translations.

- Rename TranslateOfwNodes() to TranslatePciOfwNodes(), because it is
  tightly coupled to "PCI-like" translations.

- Rename REQUIRED_OFW_NODES to REQUIRED_PCI_OFW_NODES, because this macro
  is specific to TranslatePciOfwNodes().

- Introduce a new wrapper function under the original TranslateOfwNodes()
  name. This function is supposed to try translations in some order until
  a specific translation returns a status different from
  RETURN_UNSUPPORTED.

- Introduce a new Feature PCD that controls whether PCI translation is
  attempted at all.

- The boot option "survival policy" in BootOrderComplete() must take into
  account if the user was able to select PCI-like boot options. If the
  user had no such possibility (because the Feature PCD was off for
  PCI-like translation), then we ought to keep any such unselected boot
  options.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16571 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 64 insertions, 7 deletions

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
index 2ff6854430..174fd1f554 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
@@ -35,8 +35,8 @@
 /**

   Numbers of nodes in OpenFirmware device paths that are required and examined.

 **/

-#define REQUIRED_OFW_NODES 2

-#define EXAMINED_OFW_NODES 4

+#define REQUIRED_PCI_OFW_NODES  2

+#define EXAMINED_OFW_NODES      4

 

 

 /**

@@ -539,7 +539,7 @@ ParseOfwNode (
 

 /**

 

-  Translate an array of OpenFirmware device nodes to a UEFI device path

+  Translate a PCI-like array of OpenFirmware device nodes to a UEFI device path

   fragment.

 

   @param[in]     OfwNode         Array of OpenFirmware device nodes to

@@ -571,7 +571,7 @@ ParseOfwNode (
 **/

 STATIC

 RETURN_STATUS

-TranslateOfwNodes (

+TranslatePciOfwNodes (

   IN      CONST OFW_NODE *OfwNode,

   IN      UINTN          NumNodes,

   OUT     CHAR16         *Translated,

@@ -585,7 +585,7 @@ TranslateOfwNodes (
   //

   // Get PCI device and optional PCI function. Assume a single PCI root.

   //

-  if (NumNodes < REQUIRED_OFW_NODES ||

+  if (NumNodes < REQUIRED_PCI_OFW_NODES ||

       !SubstringEq (OfwNode[0].DriverName, "pci")

       ) {

     return RETURN_UNSUPPORTED;

@@ -803,6 +803,58 @@ TranslateOfwNodes (
 

 /**

 

+  Translate an array of OpenFirmware device nodes to a UEFI device path

+  fragment.

+

+  @param[in]     OfwNode         Array of OpenFirmware device nodes to

+                                 translate, constituting the beginning of an

+                                 OpenFirmware device path.

+

+  @param[in]     NumNodes        Number of elements in OfwNode.

+

+  @param[out]    Translated      Destination array receiving the UEFI path

+                                 fragment, allocated by the caller. If the

+                                 return value differs from RETURN_SUCCESS, its

+                                 contents is indeterminate.

+

+  @param[in out] TranslatedSize  On input, the number of CHAR16's in

+                                 Translated. On RETURN_SUCCESS this parameter

+                                 is assigned the number of non-NUL CHAR16's

+                                 written to Translated. In case of other return

+                                 values, TranslatedSize is indeterminate.

+

+

+  @retval RETURN_SUCCESS           Translation successful.

+

+  @retval RETURN_BUFFER_TOO_SMALL  The translation does not fit into the number

+                                   of bytes provided.

+

+  @retval RETURN_UNSUPPORTED       The array of OpenFirmware device nodes can't

+                                   be translated in the current implementation.

+

+**/

+STATIC

+RETURN_STATUS

+TranslateOfwNodes (

+  IN      CONST OFW_NODE *OfwNode,

+  IN      UINTN          NumNodes,

+  OUT     CHAR16         *Translated,

+  IN OUT  UINTN          *TranslatedSize

+  )

+{

+  RETURN_STATUS Status;

+

+  Status = RETURN_UNSUPPORTED;

+

+  if (FeaturePcdGet (PcdQemuBootOrderPciTranslation)) {

+    Status = TranslatePciOfwNodes (OfwNode, NumNodes, Translated,

+               TranslatedSize);

+  }

+  return Status;

+}

+

+/**

+

   Translate an OpenFirmware device path fragment to a UEFI device path

   fragment, and advance in the input string.

 

@@ -1083,9 +1135,11 @@ BootOrderComplete (
           if ((Acpi->HID & PNP_EISA_ID_MASK) == PNP_EISA_ID_CONST &&

               EISA_ID_TO_NUM (Acpi->HID) == 0x0a03) {

             //

-            // drop PciRoot()

+            // drop PciRoot() if we enabled the user to select PCI-like boot

+            // options, by providing translation for such OFW device path

+            // fragments

             //

-            Keep = FALSE;

+            Keep = !FeaturePcdGet (PcdQemuBootOrderPciTranslation);

           }

         }

 

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
index 12419cda09..5aa4e6eff0 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
@@ -51,3 +51,6 @@
 

 [Guids]

   gEfiGlobalVariableGuid

+

+[FeaturePcd]

+  gUefiOvmfPkgTokenSpaceGuid.PcdQemuBootOrderPciTranslation