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 <[email protected]> --- v2: attempt at fixing code style issues OvmfPkg/Include/Library/QemuFwCfgLib.h | 21 +++++++++++ OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c | 53 +++++++++++++++++++++++++++ 2 files changed, 74 insertions(+), 0 deletions(-) diff --git a/OvmfPkg/Include/Library/QemuFwCfgLib.h b/OvmfPkg/Include/Library/QemuFwCfgLib.h index 5a3db7e..3776d79 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 b94dc67..8caab42 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; +} -- 1.7.1 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
