This patch implements Allwinner A10 SPI controller emulation.
Only master-mode functionality is implemented.
Since U-Boot and Linux SPI drivers for Allwinner A10 perform only
byte-wide CPU access (no DMA) to the transmit and receive registers of
the peripheral, the emulated controller does not implement DMA control,
and supports only byte-wide access to transmit and receive registers
(half-word and word accesses will be treated as byte accesses).
Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Message-id: 20241001221349.8319-2-strahinja.p.jankovic@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Ensure that the FIFO is checked for emptiness before popping data
from it. Previously, the code directly popped the data from the FIFO
without checking, which could cause an assertion failure:
../util/fifo8.c:67: fifo8_pop: Assertion `fifo->num > 0' failed.
Signed-off-by: Shiva sagar Myana <Shivasagar.Myana@amd.com>
Message-id: 20240924112035.1320865-1-Shivasagar.Myana@amd.com
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
[PMM: tweaked commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use device_class_set_legacy_reset() instead of opencoding an
assignment to DeviceClass::reset. This change was produced
with:
spatch --macro-file scripts/cocci-macro-file.h \
--sp-file scripts/coccinelle/device-reset.cocci \
--keep-comments --smpl-spacing --in-place --dir hw
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240830145812.1967042-8-peter.maydell@linaro.org
In this commit SPI shift engine and sequencer logic is implemented.
Shift engine performs serialization and de-serialization according to the
control by the sequencer and according to the setup defined in the
configuration registers. Sequencer implements the main control logic and
FSM to handle data transmit and data receive control of the shift engine.
Signed-off-by: Chalapathi V <chalapathi.v@linux.ibm.com>
Reviewed-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
SPI controller device model supports a connection to a single SPI responder.
This provide access to SPI seeproms, TPM, flash device and an ADC controller.
All SPI function control is mapped into the SPI register space to enable full
control by firmware. In this commit SPI configuration component is modelled
which contains all SPI configuration and status registers as well as the hold
registers for data to be sent or having been received.
An existing QEMU SSI framework is used and SSI_BUS is created.
Signed-off-by: Chalapathi V <chalapathi.v@linux.ibm.com>
Reviewed-by: Caleb Schlossin <calebs@linux.vnet.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
[np: Fix FDT macro compile for qtest]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Coverity reports a possible integer overflow because routine
aspeeed_smc_hclk_divisor() has a codepath returning 0, which could
lead to an integer overflow when computing variable 'hclk_shift' in
the caller aspeed_smc_dma_calibration().
The value passed to aspeed_smc_hclk_divisor() is always between 0 and
15 and, in this case, there is always a matching hclk divisor. Remove
the return 0 and use g_assert_not_reached() instead.
Fixes: Coverity CID 1547822
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
AST2700 fmc/spi controller's address decoding unit is 64KB
and only bits [31:16] are used for decoding. Introduce seg_to_reg
and reg_to_seg handlers for ast2700 fmc/spi controller.
In addition, adds ast2700 fmc, spi0, spi1, and spi2 class init handler.
AST2700 is a 64 bits quad core CPUs(Cortex-a35). Introduce a new
"aspeed_2700_smc_flash_ops" and set its valid "max_access_size"
8 for 64 bits data format access.
Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
It set "aspeed_smc_flash_ops" struct which containing
read and write callbacks to be used when I/O is performed
on the SMC flash region. And it set the valid max_access_size 4
by default for all ASPEED SMC models.
However, the valid max_access_size 4 only support 32 bits CPUs.
To support all ASPEED SMC model, introduce a new
"const MemoryRegionOps *" attribute in AspeedSMCClass and
use it in aspeed_smc_flash_realize function.
Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
AST2700 support the maximum dram size is 8GiB
and has a "DMA DRAM Side Address High Part(0x7C)"
register to support 64 bits dma dram address.
Add helper routines functions to compute the dma dram
address, new features and update trace-event
to support 64 bits dram address.
Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
DMA length is from 1 byte to 32MB for AST2600 and AST10x0
and DMA length is from 4 bytes to 32MB for AST2500.
In other words, if "R_DMA_LEN" is 0, it should move at least 1 byte
data for AST2600 and AST10x0 and 4 bytes data for AST2500.
To support all ASPEED SOCs, adds dma_start_length parameter to store
the start length, add helper routines function to compute the dma length
and update DMA_LENGTH mask to "1FFFFFF" to support dma 1 byte
length unit for AST2600 and AST1030.
Currently, only supports dma length 4 bytes aligned.
Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
The Aspeed SMC device model use to have a 'sdram_base' property. It
was removed by commit d177892d4a ("aspeed/smc: Remove unused
"sdram-base" property") because previous changes simplified the DMA
transaction model to use an offset in RAM and not the physical
address.
The AST2700 SoC has larger address space (64-bit) and a new register
DMA DRAM Side Address High Part (0x7C) is introduced to deal with the
high bits of the DMA address. To be able to compute the offset of the
DMA transaction, as done on the other SoCs, we will need to know where
the DRAM is mapped in the address space. Re-introduce a "dram-base"
property to hold this value.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Jamin Lin <jamin_lin@aspeedtech.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
sprintf() is deprecated on Darwin since macOS 13.0 / XCode 14.1,
resulting in painful developer experience. Use snprintf() instead.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20240411104340.6617-6-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We pass a ResetType argument to the Resettable class enter
phase method, but we don't pass it to hold and exit, even though
the callsites have it readily available. This means that if
a device cared about the ResetType it would need to record it
in the enter phase method to use later on. Pass the type to
all three of the phase methods to avoid having to do that.
Commit created with
for dir in hw target include; do \
spatch --macro-file scripts/cocci-macro-file.h \
--sp-file scripts/coccinelle/reset-type.cocci \
--keep-comments --smpl-spacing --in-place \
--include-headers --dir $dir; done
and no manual edits.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luc Michel <luc.michel@amd.com>
Message-id: 20240412160809.1260625-5-peter.maydell@linaro.org
The Aspeed machines have many Static Memory Controllers (SMC), up to
8, which can only drive flash memory devices. Commit 27a2c66c92
("aspeed/smc: Wire CS lines at reset") tried to ease the definitions
of these devices by allowing flash devices from the command line to be
attached to a SSI bus. For that, the wiring of the CS lines of the
Aspeed SMC controller was moved at reset. Two assumptions are made
though, first that the device has a SSI_GPIO_CS GPIO line, which is
not always the case, and second that it is a flash device.
Correct this problem by ensuring that the devices attached to the bus
are of the correct flash type. This fixes a QEMU abort when devices
without a CS line, such as the max111x, are passed on the command
line.
While at it, export TYPE_M25P80 used in the Xilinx Versal Virtual
machine.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2228
Fixes: 27a2c66c92 ("aspeed/smc: Wire CS lines at reset")
Reported-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
[ clg: minor fixes in the commit log ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
The OSPI DMA reads flash data through the OSPI linear address space (the
iomem_dac region), because of this the reentrancy guard introduced in
commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
the memory region.
Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
Message-id: 20240219105637.65052-1-sai.pavan.boddu@amd.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch adds the SPI controller for the BCM2835. Polling and interrupt modes
of transfer are supported. DMA and LoSSI modes are currently unimplemented.
Signed-off-by: Rayhan Faizel <rayhan.faizel@gmail.com>
Message-id: 20240129221807.2983148-2-rayhan.faizel@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The spips, qspips, and zynqmp-qspips share the same realize function
(xilinx_spips_realize) and initialize their io memory region with different
mmio_ops passed through the class. The size of the memory region is set to
the largest area (0x200 bytes for zynqmp-qspips) thus it is possible to write
out of s->regs[addr] in xilinx_spips_write for spips and qspips.
This fixes that wrong behavior.
Reviewed-by: Luc Michel <luc.michel@amd.com>
Signed-off-by: Frederic Konrad <fkonrad@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Message-id: 20231124143505.1493184-2-fkonrad@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We currently don't clear the interrupts if they are disabled. This means
that if an interrupt occurs and the guest disables interrupts the QEMU
IRQ will remain high.
This doesn't immediately affect guests, but if the
guest re-enables interrupts it's possible that we will miss an
interrupt as it always remains set.
Let's update the logic to always call qemu_set_irq() even if the
interrupts are disabled to ensure we set the level low. The level will
never be high unless interrupts are enabled, so we won't generate
interrupts when we shouldn't.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231102003424.2003428-2-alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This to avoid indexes conflicts on the same SSI bus. Adapt machines
using multiple devices on the same bus to avoid breakage.
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Currently, a set of default flash devices is created at machine init
and drives defined on the QEMU command line are associated to the FMC
and SPI controllers in sequence :
-drive file<file>,format=raw,if=mtd
-drive file<file1>,format=raw,if=mtd
The CS lines are wired in the same creation loop. This makes a strong
assumption on the ordering and is not very flexible since only a
limited set of flash devices can be defined : 1 FMC + 1 or 2 SPI,
which is less than what the SoC really supports.
A better alternative would be to define the flash devices on the
command line using a blockdev attached to a CS line of a SSI bus :
-blockdev node-name=fmc0,driver=file,filename=./flash.img
-device mx66u51235f,cs=0x0,bus=ssi.0,drive=fmc0
However, user created flash devices are not correctly wired to their
SPI controller and consequently can not be used by the machine. Fix
that and wire the CS lines of all available devices when the SSI bus
is reset.
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Simple routine to retrieve a DeviceState object on a SPI bus using its
CS index. It will be useful for the board to wire the CS lines.
Cc: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Boards will use this new property to identify the device CS line and
wire the SPI controllers accordingly.
Cc: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
We use the user_ss[] array to hold the user emulation sources,
and the softmmu_ss[] array to hold the system emulation ones.
Hold the latter in the 'system_ss[]' array for parity with user
emulation.
Mechanical change doing:
$ sed -i -e s/softmmu_ss/system_ss/g $(git grep -l softmmu_ss)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230613133347.82210-10-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
It's cleaner and removes the curious '+ 1' required to skip the DMA
IRQ line of the controller.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Nuvoton's PSPI is a general purpose SPI module which enables
connections to SPI-based peripheral devices.
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Chris Rauer <crauer@google.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@linaro.org>
Message-id: 20230208235433.3989937-3-wuhaotsh@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Include "hw/registerfields.h" in the .c files instead (if needed).
Message-Id: <20230210112315.1116966-1-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The 'hwaddr' type is defined in "exec/hwaddr.h" as:
hwaddr is the type of a physical address
(its size can be different from 'target_ulong').
All definitions use the 'HWADDR_' prefix, except TARGET_FMT_plx:
$ fgrep define include/exec/hwaddr.h
#define HWADDR_H
#define HWADDR_BITS 64
#define HWADDR_MAX UINT64_MAX
#define TARGET_FMT_plx "%016" PRIx64
^^^^^^
#define HWADDR_PRId PRId64
#define HWADDR_PRIi PRIi64
#define HWADDR_PRIo PRIo64
#define HWADDR_PRIu PRIu64
#define HWADDR_PRIx PRIx64
#define HWADDR_PRIX PRIX64
Since hwaddr's size can be *different* from target_ulong, it is
very confusing to read one of its format using the 'TARGET_FMT_'
prefix, normally used for the target_long / target_ulong types:
$ fgrep TARGET_FMT_ include/exec/cpu-defs.h
#define TARGET_FMT_lx "%08x"
#define TARGET_FMT_ld "%d"
#define TARGET_FMT_lu "%u"
#define TARGET_FMT_lx "%016" PRIx64
#define TARGET_FMT_ld "%" PRId64
#define TARGET_FMT_lu "%" PRIu64
Apparently this format was missed during commit a8170e5e97
("Rename target_phys_addr_t to hwaddr"), so complete it by
doing a bulk-rename with:
$ sed -i -e s/TARGET_FMT_plx/HWADDR_FMT_plx/g $(git grep -l TARGET_FMT_plx)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230110212947.34557-1-philmd@linaro.org>
[thuth: Fix some warnings from checkpatch.pl along the way]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230109140306.23161-4-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Store a reference on the AspeedSMC class under the flash object and
use it when accessing the flash contents. Avoiding the class cast
checkers in these hot paths improves performance by 10% when running
the aspeed avocado tests.
Message-Id: <20220923084803.498337-7-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Investigating why some BMC models are so slow compared to a plain ARM
virt machines I did some profiling of:
./qemu-system-arm -M romulus-bmc -nic user \
-drive
file=obmc-phosphor-image-romulus.static.mtd,format=raw,if=mtd \
-nographic -serial mon:stdio
And saw that object_class_dynamic_cast_assert was dominating the
profile times. We have a number of cases in this model of the SSI bus.
As the class is static once the object is created we just cache it and
use it instead of the dynamic case macros.
Profiling against:
./tests/venv/bin/avocado run \
tests/avocado/machine_aspeed.py:test_arm_ast2500_romulus_openbmc_v2_9_0
Before: 35.565 s ± 0.087 s
After: 15.713 s ± 0.287 s
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220811151413.3350684-6-alex.bennee@linaro.org>
Message-Id: <20220923084803.498337-6-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This patch adds the `rw1c` functionality to the respective
registers. The status fields are cleared when the respective
field is set.
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220930033241.206581-3-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch addresses the coverity issues specified in [1],
as suggested, `FIELD_DP32()`/`FIELD_EX32()` macros have been
implemented to clean up the code.
[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg887713.html
Fixes: Coverity CID 1488107
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-Id: <20220930033241.206581-2-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Updates the `EVENT_ENABLE` register to offset `0x34` as per
OpenTitan spec [1].
[1] https://docs.opentitan.org/hw/ip/spi_host/doc/#Reg_event_enable
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220823061201.132342-5-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch fixes up minor typos in ibex_spi_host
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-Id: <20220823061201.132342-2-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Coverity warns that "ssi_transfer(s->spi, 0U) << 8 * i" might overflow
because the expression is evaluated using 32-bit arithmetic and then
used in a context expecting a uint64_t.
Fixes: Coverity CID 1487244
Message-Id: <20220628165512.1133590-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
AST1030 spi controller's address decoding unit is 1MB that is identical
to ast2600, but fmc address decoding unit is 512kb.
Introduce seg_to_reg and reg_to_seg handlers for ast1030 fmc controller.
In addition, add ast1030 fmc, spi1, and spi2 class init handler.
Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220401083850.15266-3-jamin_lin@aspeedtech.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Adds the SPI_HOST device model for ibex. The device specification is as per
[1]. The model has been tested on opentitan with spi_host unit tests
written for TockOS.
[1] https://docs.opentitan.org/hw/ip/spi_host/doc/
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220303045426.511588-1-alistair.francis@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220307071856.1410731-7-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
If no id is provided, qdev automatically assigns an unique name with
the following pattern "<type>.<index>" which avoids bus name collision
when using multiple buses.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220307071856.1410731-6-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The naming makes more sense in a SPI controller model.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220307071856.1410731-5-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
It is not used anymore.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220307071856.1410731-4-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
