This implementation corrects the GPE DWx mapping for GPIO groups.
The assignments is done in GPIO MISCFG register for all GPIO communities.
And configures the which GPIO communities get register as Tier1.
Change-Id: I9c306d46e5194944def26c24cdb95f5ebada42b8
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32508
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
This patch ports CB:32275 changes from CNL to ICL.
Ice Lake require that FSP-M component should be
XIP. This change selects FSP_M_XIP so that the right arguments are
passed into cbfstool when adding this component.
Change-Id: Icc5550f1f94957fa1b28c8bba6fc0efee98e233e
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32507
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-by: Ronak Kanabar <ronak.kanabar@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This patch ports CB:31787 and CB:31908 changes from CNL to ICL.
This change moves soc_fill_power_state and soc_prev_sleep_state to
pmutil.c. It allows the functions to be used across romstage and smm.
Also fix GEN_PMCON bit checks as below:
ICL PCH has PWR_FLR, SUS_PWR_FLR and HOST_RST_STS bits in GEN_PMCON_A
and so this change updates the check for these bits to use GEN_PMCON_A
instead of GEN_PMCON_B.
Change-Id: Ib7ab95b7bbcc97a076d27a11db2105f7b976b521
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32506
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This patch ports CB:30718 and CB:31908 changes from CNL to ICL.
Add logging of chipset events on boot into the flash event log.
This was tested on a google/dragonegg board to ensure that events
like "System Reset" are added to the log as expected.
Also fix GEN_PMCON bit checks as below:
ICL PCH has PWR_FLR, SUS_PWR_FLR and HOST_RST_STS bits in GEN_PMCON_A
and so this change updates the check for these bits to use GEN_PMCON_A
instead of GEN_PMCON_B.
Change-Id: I25ec32e81f8801f8d5e69c6095ffed73d75dded6
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32504
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
This patch ports CB:31902 changes from CNL to ICL.
The prev_sleep_state value was showing 5 even after warm reboot, once the
SUS_PWR_FLR bit is being set. This bit was not being cleared.
Hence clearing the PMCON status bits.
Change-Id: Ia07aa17b4491216a277c36edfe6ed2aa489287c6
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32503
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Commit 351e3e5 ("src: Use include <console/console.h> when appropriate")
has broken the build here, see below, so we include console.h here again.
In file included from src/device/oprom/x86emu/x86emui.h:65,
from src/device/oprom/x86emu/debug.c:40:
src/device/oprom/x86emu/debug.c: In function 'x86emu_dump_regs':
src/device/oprom/x86emu/debug.h:46:22: error: implicit declaration of function 'printk'; did you mean 'printf'?
[-Werror=implicit-function-declaration]
#define printf(x...) printk(BIOS_DEBUG, x)
^~~~~~
src/device/oprom/x86emu/debug.c:366:5: note: in expansion of macro 'printf'
printf("\tAX=%04x ", M.x86.R_AX );
^~~~~~
Fixes: 351e3e5 ("src: Use include <console/console.h> when appropriate")
Change-Id: I75d0b7c08bfa6dcb07778bbb762223b62cfc3da7
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32499
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Chromebook doesn't require support wake on LAN in S5.
Disable it by default for power saving.
BUG=b:131571666
TEST= check LAN indicator is off under S5
Signed-off-by: Eric Lai <ericr_lai@compal.corp-partner.google.com>
Change-Id: Ia90c9d2f3ea9b3580e9a7bbfb47c917dd51e3c03
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32502
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
a 1M CBFS size is inadequate when adding the FSP binary to
image due to default FSP location in CBFS, so bump to 2M
to ensure autobuilds succeed.
Change-Id: I0683bea43cc71fad32bc42bfbd72f3913256d53c
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32525
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
For GPIO pads that are configured as no-connect (PAD_NC), setting it
as GPI (with Rx enabled) leads to GPE0_STS being set
incorrectly. Though this is not an issue in practice (GPE0_EN is not
set, so no events triggered), it can confuse users when debugging GPE
related issues.
This change configures PAD_NC to have Rx disabled along with Tx to
ensure that it does not end up setting GPE0_STS bits for unwanted
GPIO pads.
P.S.: IOSSTATE config does not have a TxDRxD setting, so leaving that
configuration as is.
BUG=b:129235068
TEST=Verified that GPE0_STS bits are not set for pads that are marked
as PAD_NC.
Change-Id: I726cc7b86a94e7449352cd8a8806d4d775c593dc
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32514
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Ronak Kanabar <ronak.kanabar@intel.com>
Add more registers and make them optional, so they keep untouched/
their default if omitted.
Change-Id: I5d8008176d2972976b387c558658b8e70b50af8e
Signed-off-by: Max Blau <tripleshiftone@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32376
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Increase ramstage to 2M, required to actually embed the 7.2mb uImage
into the coreboot.rom, increase the postram cbfs cache in order for the
fit image to be loadable (without this increase the fit payload is found
but not loaded)
Change-Id: Iee0ed9f7958588ceda54bb32253c84cac68abea2
Signed-off-by: Marty E. Plummer <hanetzer@startmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32373
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
The name OPROM is somewhat inaccurate, since other steps to bring
up display and graphics are needed depending on mainboard/SoC.
This patch cleans up OPROM code nomenclature, and works towards
the goal of deprecating vboot1:
* Rename CONFIG_VBOOT_OPROM_MATTERS to
CONFIG_VBOOT_MUST_REQUEST_DISPLAY and clarify Kconfig
description
* Remove function vboot_handoff_skip_display_init
* Remove use of the VbInit oflag VB_INIT_OUT_ENABLE_DISPLAY
* Add |flags| field to vboot_working_data struct
* Create VBOOT_FLAG_DISPLAY_REQUESTED and set in vboot_handoff
BUG=b:124141368, b:124192753, chromium:948529
TEST=make clean && make test-abuild
TEST=build and flash eve device; attempt loading dev/rec modes
BRANCH=none
Change-Id: Idf111a533c3953448b4b9084885a9a65a2432a8b
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32262
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Patch corrects IRQ and GPIO configuration for RT5682 codec's Jack INT.
Switching IOAPIC to GpioInt because ACPI Interrupt() doesn't support
jack triggering on both edges.
BUG=b:130180492
TEST=build and boot on a CML EVT board.
Use evtest & verify headset jack detection functions as expected.
Change-Id: Ia9bf8d554b54554f9ac1e78fd44a508964c8a14d
Signed-off-by: Naveen Manohar <naveen.m@intel.com>
Suggested-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32474
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Shelley Chen <shchen@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Trusted Firmware places some components in SRAM on RK3399 and therefore
restricts accesses to SRAM to the secure world. This makes the vboot
working data inaccessible to normal world payloads, so we need to
migrate it into CBMEM.
Change-Id: Ic7c95790f2f118ccbdd897550f13b5f987bdd831
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32490
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Joel Kitching <kitching@google.com>
Implement mt_pll_raise_ca53_freq() in MT8183 to raise the CPU frequency.
Move the function declaration to common header.
BUG=b:80501386
BRANCH=none
Test=Boots correctly on Kukui
Change-Id: Ide8d767486d68177fa2bfbcc5b559879eca1bcda
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32465
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
With the default CPU voltage (0.8v), CPU frequency should be 1417Mhz at
most. We have to raise CPU frequency to 1989MHz after increasing CPU
voltage to 1.05v in romstage.
BUG=b:80501386
BRANCH=none
Test=Boots correctly on Kukui
Change-Id: I4c3e0fa27ccda8e0efe422b6ab503a1efb1697e9
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32464
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
NEED_VB20_INTERNALS should always be specified when peeking
into vboot internal data structures.
BUG=b:124141368, chromium:956474
TEST=make clean && make test-abuild
BRANCH=none
Change-Id: I5a47a28350fd5a68efeff0d06ca150c1ae145412
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32452
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Disable the GBB flag forcing manual recovery now that we can read
the manual recovery from H1.
Enable the GBB flag to skip EC software sync, since images built
from coreboot.org do not include the EC binaries by default.
Change-Id: I0e1d6304e3e29eda68c7b807cf0774275c37d710
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32476
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
We do not want the RX signal to be floating on the board as that could
cause the ISH to remain in a higher power state (because there is logic
to keep the ISH in an higher power state when there is an active UART).
Add an internal 20K pull up on the RX line. In normal configuration this
will burn an additional 544uW.
BRANCH=R75
BUG=b:131241969
TEST=verify that ISH console still works with rework
Change-Id: Ifc9621bcafe4c86edfa9cd6d58b307254d3a81ca
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32471
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
If the Intel IGD device pci 02.0 is disabled or undefined in
the device tree, then internal graphics pre-allocated memory
and GFX-VT MMIO memory for virtualization won`t be allocated
in the SoC address space.
Thus, patch resolves the FSP-S hang problem on Skylake/ Kaby
Lake processors when the IGD device is disabled. This should
provide to run FSP 2.0-based coreboot on these CPUs families
without integrated graphics card.
The following boards were used for testing:
- Asrock H110M-DVS board (desktop i5-6600) & NVIDIA GTX 1060
as external GPU.
Virtualization and GFX 3D acceleration with nouveau driver
still works well (tested on VirtualBox 5.1.38 with Ubuntu
18.04.1 as guest and host OS)
- Intel KBL-R U RVP board (mobile i5-8350u) without GFX.
Payload: tianocore edk2-stable201811-216-g51be9d0.
Change-Id: Id7a0cba582d83e3fe7e8d20342ee219cdd369a53
Signed-off-by: Maxim Polyakov <max.senia.poliak@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32467
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This patch adds the setting of psys_pmax to 136W. According to the
design, Rpsys is 11.8Kohm. Here is the equation to come out the
Psys_pmax value: Psys_pmax * 1.493uA/W * 11.8Kohm / 2 = 1.2V
Hence, Psys_pmax is 136W.
BUG=b:124792558
BRANCH=None
TEST=emerge-sarien coreboot chromeos-bootimage & Ensure the value is
passed to FSP by enabling FSP log & Boot into the OS
Change-Id: Id3f6be5f0c2346a7763195a992c0ae45faede056
Signed-off-by: Gaggery Tsai <gaggery.tsai@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32457
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Clear the GPI Interrupt Status & Enable registers to prevent any
interrupt storms due to GPI.
BUG=b:130593883
BRANCH=octopus
TEST=Ensure that the Interrupt status & enable registers are reset
during the boot up when the system is brought out of G3, S5 & S3. Ensure
that the system boots fine to ChromeOS.
Change-Id: Ia3b9d3bf08472219348e20b53bae470c589039fb
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32448
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Add support to reset the GPI Interrupt Status & Enable registers so that
the system does not experience any interrupt storm from a GPI when it
comes out of one of the sleep states.
BUG=b:130593883
BRANCH=None
TEST=Ensure that the Interrupt status & enable registers are reset
during the boot up. Ensure that the system boots fine to ChromeOS.
Change-Id: I99f36d88cbab8bb75f12ab1a4d06437f837841cb
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32447
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Add the offset information for GPI interrupt status and enable register
in the pad_community structure. Populate the concerned information for
individual SoCs. This offset information is required to clear the
interrupt configuration during the bootup.
BUG=b:130593883
BRANCH=None
TEST=Ensure that the interrupt configuration are cleared during bootup.
Ensured that the system boots to ChromeOS.
Change-Id: I8af877a734e8d49b700d720b736da8764985a8f8
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32446
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
We only grep'ed for "ACPI Warning" resulting in an actual more severe
"ACPI Error" being ignored.
Change-Id: I9cec8a388f5558b1ffc383cc2fc69405252cbb37
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32469
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
The ACPI code of LPE device is included regardless of the
availability of the LPE controller.
Linux remains requesting the status of device LPEA even if
this device is disabled.
Include ACPI LPE controller code at Braswell mainboards with
LPE enabled.
BUG=N/A
TEST=Linux 4.17+ on Portwell PQ7-M107
Change-Id: Ic8acf9ea9e9b0ba9b272e20beb2023b7a4716a73
Signed-off-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/29414
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
The dqs_map array is used only for LPDDR3 and LPDDR4. It is not used for
DDR4, and so it can be removed from the baseboard memory initialization
code.
BRANCH=none
BUG=b:129706819
TEST=ensure the firmware builds without error; I don't have hardware
available to test this just yet.
Change-Id: I07fac3097d68f37b4630d3f0010f987da2f03bd7
Signed-off-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32484
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
First configuration supported is 8 GB system memory:
4 x 2 GB (K4E6E304ED-EGCG).
BRANCH=none
BUG=b:129706819
TEST=ensure the firmware builds without error; I don't have hardware
available to test this just yet.
Signed-off-by: Paul Fagerburg <pfagerburg@chromium.org>
Change-Id: Ibd92d585118ff75492e8a7188dcdb2a286836d56
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32364
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Intel's DQ_DQS_RComp_Info_Utility generates data for 6 entries. MRC will
return errors if we don't have all 6 entries in the map.
BRANCH=none
BUG=b:131103736
TEST=ensure the firmware builds without error; I don't have hardware
available to test this just yet.
Change-Id: I20a768de0e4440d7dde7b717794c4e2d0c62819c
Signed-off-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32475
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Changes includes:
- enable TPM1 + add entry in devicetree
- configure LPC IO to make IPMI work + add entry in devicetree
- introduce DSDT and SMBIOS entries for IPMI to make it detectable
by ipmi_si driver
Signed-off-by: Lukasz Siudut <lsiudut@fb.com>
Change-Id: Ia975643064075f1f861f4ead6f24ed71f345ea04
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32443
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Enable LTR for NVMe so it can use ASPM L1.2.
BUG=b:127593309
TEST=build and boot on sarien and check L1 substate with lspci
before: L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2- ASPM_L1.1+
after: L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
Change-Id: I9842beda6767f758556747f83cfcedbd00612698
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32456
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-by: Roy Mingi Park <roy.mingi.park@intel.com>
Remapping Hardware Status Affinity (RHSA) structure is applicable for
platforms supporting non-uniform memory. An ACPI Name-space Device
Declaration (ANDD) structure uniquely represents an ACPI name-space
enumerated device capable of issuing DMA requests in the platform.
Add RHSA and ANDD structures support for DMAR table generation.
BUG=b:130351429
TEST=Image built and booted to kernel
Change-Id: I042925a7c03831061870d9bca03f11bf25aeb3e7
Signed-off-by: John Zhao <john.zhao@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32189
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Furquan Shaikh <furquan@google.com>
The IRQ tables don't support this path, so we shouldn't report presence
of the legacy PICs. As the _PIC method is optional and we ignore the
passed parameter anyway, drop it.
Change-Id: I51301a600e16f74fde00fdcb4595e1f47a52e207
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/29833
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Lance Zhao <lance.zhao@gmail.com>
Subrata Banik