From: jljusten <jljusten@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Mon, 23 Jul 2012 17:10:29 +0000 (+0000)
Subject: OvmfPkg: introduce QemuFwCfgFindFile ()
X-Git-Tag: edk2-stable201903~13229
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=0ac9bc9be45eace87fa43d395889274051badccc

OvmfPkg: introduce QemuFwCfgFindFile ()

Tested with the "bootorder" fw_cfg file. Example contents (leading space
added and line terminators transcribed for readability):

  /pci@i0cf8/ide@1,1/drive@0/disk@0<LF>
  /pci@i0cf8/ide@1,1/drive@1/disk@0<LF>
  /pci@i0cf8/ethernet@3/ethernet-phy@0<NUL>

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

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13549 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/OvmfPkg/Include/Library/QemuFwCfgLib.h b/OvmfPkg/Include/Library/QemuFwCfgLib.h
index 5a3db7e809..3776d79ea9 100644
--- a/OvmfPkg/Include/Library/QemuFwCfgLib.h
+++ b/OvmfPkg/Include/Library/QemuFwCfgLib.h
@@ -41,6 +41,7 @@ typedef enum {
   QemuFwCfgItemKernelSetupAddress   = 0x0016,
   QemuFwCfgItemKernelSetupSize      = 0x0017,
   QemuFwCfgItemKernelSetupData      = 0x0018,
+  QemuFwCfgItemFileDir              = 0x0019,
 
   QemuFwCfgItemX86AcpiTables        = 0x8000,
   QemuFwCfgItemX86SmbiosTables      = 0x8001,
@@ -153,5 +154,25 @@ QemuFwCfgRead64 (
   );
 
 
+/**
+  Find the configuration item corresponding to the firmware configuration file.
+
+  @param[in]  Name - Name of file to look up.
+  @param[out] Item - Configuration item corresponding to the file, to be passed
+                     to QemuFwCfgSelectItem ().
+  @param[out] Size - Number of bytes in the file.
+
+  @return    RETURN_SUCCESS       If file is found.
+             RETURN_NOT_FOUND     If file is not found.
+             RETURN_UNSUPPORTED   If firmware configuration is unavailable.
+
+**/
+RETURN_STATUS
+EFIAPI
+QemuFwCfgFindFile (
+  IN   CONST CHAR8           *Name,
+  OUT  FIRMWARE_CONFIG_ITEM  *Item,
+  OUT  UINTN                 *Size
+  );
 #endif
 
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
index b94dc67392..8caab42e8b 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -244,3 +244,56 @@ QemuFwCfgInitialize (
   DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));
   return RETURN_SUCCESS;
 }
+
+
+/**
+  Find the configuration item corresponding to the firmware configuration file.
+
+  @param[in]  Name - Name of file to look up.
+  @param[out] Item - Configuration item corresponding to the file, to be passed
+                     to QemuFwCfgSelectItem ().
+  @param[out] Size - Number of bytes in the file.
+
+  @return    RETURN_SUCCESS       If file is found.
+             RETURN_NOT_FOUND     If file is not found.
+             RETURN_UNSUPPORTED   If firmware configuration is unavailable.
+
+**/
+RETURN_STATUS
+EFIAPI
+QemuFwCfgFindFile (
+  IN   CONST CHAR8           *Name,
+  OUT  FIRMWARE_CONFIG_ITEM  *Item,
+  OUT  UINTN                 *Size
+  )
+{
+  UINT32 Count;
+  UINT32 Idx;
+
+  if (!mQemuFwCfgSupported) {
+    return RETURN_UNSUPPORTED;
+  }
+
+  QemuFwCfgSelectItem (QemuFwCfgItemFileDir);
+  Count = SwapBytes32 (QemuFwCfgRead32 ());
+
+  for (Idx = 0; Idx < Count; ++Idx) {
+    UINT32 FileSize;
+    UINT16 FileSelect;
+    UINT16 FileReserved;
+    CHAR8  FName[56];
+
+    FileSize     = QemuFwCfgRead32 ();
+    FileSelect   = QemuFwCfgRead16 ();
+    FileReserved = QemuFwCfgRead16 ();
+    InternalQemuFwCfgReadBytes (sizeof (FName), FName);
+
+    if (AsciiStrCmp (Name, FName) == 0) {
+      *Item = SwapBytes16 (FileSelect);
+      *Size = SwapBytes32 (FileSize);
+      return RETURN_SUCCESS;
+    }
+  }
+
+  return RETURN_NOT_FOUND;
+}