audk/OvmfPkg/Library/QemuFwCfgLib
Laszlo Ersek fcca9f67fb OvmfPkg/QemuFwCfgLib: add QemuFwCfgSkipBytes()
Introduce the new public API QemuFwCfgSkipBytes(), for advancing over
bytes in the selected firmware configuration item without transferring
data between the item and the caller.

When the DMA interface is available (the common case), the operation is
instantaneous. As a fallback, provide a loop of chunked reads into a small
stack-allocated scratch buffer.

This patch enables OvmfPkg/QemuFwCfgLib to overwrite part of a writeable
fw_cfg file, which will be particularly useful for the upcoming
QEMU_LOADER_WRITE_POINTER command in OvmfPkg/AcpiPlatformDxe.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=359
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
2017-01-31 00:14:35 +01:00
..
QemuFwCfgLib.c OvmfPkg/QemuFwCfgLib: add QemuFwCfgSkipBytes() 2017-01-31 00:14:35 +01:00
QemuFwCfgLib.inf OvmfPkg: Modify QemuFwCfgLib to use new IoLib class library 2017-01-17 10:11:41 +08:00
QemuFwCfgLibInternal.h OvmfPkg/QemuFwCfgLib: support QEMU's DMA-like fw_cfg access method 2016-12-05 19:44:56 +01:00
QemuFwCfgPeiDxe.c OvmfPkg/QemuFwCfgLib: support QEMU's DMA-like fw_cfg access method 2016-12-05 19:44:56 +01:00
QemuFwCfgSec.c OvmfPkg/QemuFwCfgLib: support QEMU's DMA-like fw_cfg access method 2016-12-05 19:44:56 +01:00
QemuFwCfgSecLib.inf OvmfPkg: Modify QemuFwCfgLib to use new IoLib class library 2017-01-17 10:11:41 +08:00