There are cases when we don't want to use a system register mapped
generic timer, but can't use the SP804. For example, when using KVM on
aarch64, we want to intercept accesses to the generic timer, but can't
do so if it is using the system register interface. In such cases,
we need to use a memory-mapped generic timer.
This changeset adds a device model that implements the memory mapped
generic timer interface. The current implementation only supports a
single frame (i.e., one virtual timer and one physical timer).
The generic timer model currently does not support virtual
counters. Virtual and physical counters both tick with the same
frequency. However, virtual timers allow a hypervisor to set an offset
that is subtracted from the counter when it is read. This enables the
hypervisor to present a time base that ticks with virtual time in the
VM (i.e., doesn't tick when the VM isn't running). Modern Linux
kernels generally assume that virtual counters exist and try to use
them by default.
This changeset cleans up the generic timer a bit and moves most of the
register juggling from the ISA code into a separate class in the same
source file as the rest of the generic timer. It also removes the
assumption that there is always 8 or fewer CPUs in the system. Instead
of having a fixed limit, we now instantiate per-core timers as they
are requested. This is all in preparation for other patches that add
support for virtual timers and a memory mapped interface.
Some versions of the kernel incorrectly swap the red and blue color
select registers. This changeset adds a workaround for that by
swapping them when instantiating a PixelConverter.
Currently, frame buffer handling in gem5 is quite ad hoc. In practice,
we pass around naked pointers to raw pixel data and expect consumers
to convert frame buffers using the (broken) VideoConverter.
This changeset completely redesigns the way we handle frame buffers
internally. In summary, it fixes several color conversion bugs, adds
support for more color formats (e.g., big endian), and makes the code
base easier to follow.
In the new world, gem5 always represents pixel data using the Pixel
struct when pixels need to be passed between different classes (e.g.,
a display controller and the VNC server). Producers of entire frames
(e.g., display controllers) should use the FrameBuffer class to
represent a frame.
Frame producers are expected to create one instance of the FrameBuffer
class in their constructors and register it with its consumers
once. Consumers are expected to check the dimensions of the frame
buffer when they consume it.
Conversion between the external representation and the internal
representation is supported for all common "true color" RGB formats of
up to 32-bit color depth. The external pixel representation is
expected to be between 1 and 4 bytes in either big endian or little
endian. Color channels are assumed to be contiguous ranges of bits
within each pixel word. The external pixel value is scaled to an 8-bit
internal representation using a floating multiplication to map it to
the entire 8-bit range.
This patch introduces a UFS host controller and a UFS device. More
information about the UFS standard can be found at the JEDEC site:
http://www.jedec.org/standards-documents/results/jesd220
Note that the model does not implement the complete standard, and as
such is not an actual implementation of UFS. The following SCSI
commands are implemented: inquiry, read, read capacity, report LUNs,
start/stop, test unit ready, verify, write, format unit, send
diagnostic, synchronize cache, mode select, mode sense, request sense,
unmap, write buffer and read buffer. This is sufficient for usage with
Linux and Android.
To interact with this model a kernel version 3.9 or above is
needed.
This adds a NAND flash timing model. This model takes the number of
planes into account and is ultimately intended to be used as a
high-level performance model for any device using flash. To access the
memory, use either readMemory or writeMemory.
To make use of the model you will need an interface model
such as UFSHostDevice, which is part of a separate patch.
At the moment the flash device is part of the ARM device tree since
the only use if the UFSHostDevice, and that in turn relies on the ARM
GIC.
This patch adds an example configuration in ext/sst/tests/ that allows
an SST/gem5 instance to simulate a 4-core AArch64 system with SST's
memHierarchy components providing all the caches and memories.
This patch adds a new PIO-accessible GICv2m shim. This shim has a PIO
slave port on one side, and SPI 'wires' on the other. It accepts MSIs
from the system and triggers SPIs on the GIC. It is configurable with
a number of frames, each of which has a number of SPIs and a base SPI
offset.
A Linux driver for GICv2m is available upstream.
This patch removes the code that added this magic register. A
follow-up patch provides a GICv2m MSI shim that gives the same
functionality in a standard ARM system architecture way.
The ARM PL011 UART model didn't clear and raise interrupts
correctly. This changeset rewrites the whole interrupt handling and
makes it both simpler and fixes several cases where the correct
interrupts weren't raised or cleared. Additionally, it cleans up many
other aspects of the code.
Move the (common) GIC initialization code that notifies the platform
code of the new GIC to the base class (BaseGic) instead of the Pl390
implementation.
This change includes edits to MC146818 timer to prevent RTC events
firing before startup to comply with SimObject initialization call sequence.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
This patch cleans up the packet memory allocation confusion. The data
is always allocated at the requesting side, when a packet is created
(or copied), and there is never a need for any device to allocate any
space if it is merely responding to a paket. This behaviour is in line
with how SystemC and TLM works as well, thus increasing
interoperability, and matching established conventions.
The redundant calls to Packet::allocate are removed, and the checks in
the function are tightened up to make sure data is only ever allocated
once. There are still some oddities in the packet copy constructor
where we copy the data pointer if it is static (without ownership),
and allocate new space if the data is dynamic (with ownership). The
latter is being worked on further in a follow-on patch.
Another churn to clean up undefined behaviour, mostly ARM, but some
parts also touching the generic part of the code base.
Most of the fixes are simply ensuring that proper intialisation. One
of the more subtle changes is the return type of the sign-extension,
which is changed to uint64_t. This is to avoid shifting negative
values (undefined behaviour) in the ISA code.
This patch provides an Energy Controller device that provides software
(driver) access to a DVFS handler. The device is currently residing in
the dev/arm tree, but there is nothing inherently ARM specific in the
behaviour. It is currently only tested and supported for ARM Linux,
hence the location.
This patch closes a number of space gaps in debug messages caused by
the incorrect use of line continuation within strings. (There's also
one consistency change to a similar, but correct, use of line
continuation)
This change adds support for a generic pci host bus driver that
has been included in recent Linux kernel instead of the more
bespoke one we've been using to date. It also works with
aarch64 so it provides PCI support for 64-bit ARM Linux.
To make this work a new configuration option pci_io_base is added
to the RealView platform that should be set to the start of
the memory used as memory mapped IO ports (IO ports that are
memory mapped, not regular memory mapped IO). And a parameter
pci_cfg_gen_offsets which specifies if the config space
offsets should be used that the generic driver expects.
To use the pci-host-generic device you need to:
pci_io_base = 0x2f000000 (Valid for VExpress EMM)
pci_cfg_gen_offsets = True
and add the following to your device tree:
pci {
compatible = "pci-host-ecam-generic";
device_type = "pci";
#address-cells = <0x3>;
#size-cells = <0x2>;
#interrupt-cells = <0x1>;
//bus-range = <0x0 0x1>;
// CPU_PHYSICAL(2) SIZE(2)
// Note, some DTS blobs only support 1 size
reg = <0x0 0x30000000 0x0 0x10000000>;
// IO (1), no bus address (2), cpu address (2), size (2)
// MMIO (1), at address (2), cpu address (2), size (2)
ranges = <0x01000000 0x0 0x00000000 0x0 0x2f000000 0x0 0x10000>,
<0x02000000 0x0 0x40000000 0x0 0x40000000 0x0 0x10000000>;
// With gem5 we typically use INTA/B/C/D one per device
interrupt-map = <0x0000 0x0 0x0 0x1 0x1 0x0 0x11 0x1
0x0000 0x0 0x0 0x2 0x1 0x0 0x12 0x1
0x0000 0x0 0x0 0x3 0x1 0x0 0x13 0x1
0x0000 0x0 0x0 0x4 0x1 0x0 0x14 0x1>;
// Only match INTA/B/C/D and not BDF
interrupt-map-mask = <0x0000 0x0 0x0 0x7>;
};
The first DPRINTF() in PL390::writeDistributor always read a uint32_t, though a
packet may have only been 1 or 2 bytes. This caused an assertion in
packet->get().
This patch changes the default pixel clock to effectively generate
1080p resolution at 60 frames per second. It is dependent upon the
kernel device tree file using the specified resolution / display
string in the comments.
This is a quick hack to communicate a greater number of CPUs to a guest OS via
the ARM A9 SCU config register. Some OSes (Linux) just look at the bottom field
to count CPUs and with a small change can look at bits [3:0] to learn about up
to 16 CPUs.
Very much unsupported (and contains warning messages as such) but useful for
running 8 core sims without hardwiring CPU count in the guest OS.
Note: AArch64 and AArch32 interworking is not supported. If you use an AArch64
kernel you are restricted to AArch64 user-mode binaries. This will be addressed
in a later patch.
Note: Virtualization is only supported in AArch32 mode. This will also be fixed
in a later patch.
Contributors:
Giacomo Gabrielli (TrustZone, LPAE, system-level AArch64, AArch64 NEON, validation)
Thomas Grocutt (AArch32 Virtualization, AArch64 FP, validation)
Mbou Eyole (AArch64 NEON, validation)
Ali Saidi (AArch64 Linux support, code integration, validation)
Edmund Grimley-Evans (AArch64 FP)
William Wang (AArch64 Linux support)
Rene De Jong (AArch64 Linux support, performance opt.)
Matt Horsnell (AArch64 MP, validation)
Matt Evans (device models, code integration, validation)
Chris Adeniyi-Jones (AArch64 syscall-emulation)
Prakash Ramrakhyani (validation)
Dam Sunwoo (validation)
Chander Sudanthi (validation)
Stephan Diestelhorst (validation)
Andreas Hansson (code integration, performance opt.)
Eric Van Hensbergen (performance opt.)
Gabe Black
The VE motherboard provides a set of system control registers through which
various motherboard and coretile registers are accessed. Voltage regulators and
oscillator (DLL/PLL) config are examples. These registers must be impleted to
boot Linux 3.9+ kernels.
The underlying assumption that all PPIs must be edge-triggered is
strained when the architected timers and VGIC interfaces make
level-behaviour observable. For example, a virtual timer interrupt
'goes away' when the hypervisor is entered and the vtimer is disabled;
this requires a PPI to be de-activated.
The new method simply clears the interrupt pending state.
There is an option to enable/disable all framebuffer dumps, but the
last frame always gets dumped in the run folder with no other way to
disable it. These files can add up very quickly running many experiments.
This patch adds an option to disable them. The default behavior
remains unchanged.
This patch changes the default parameter value of conf_table_reported
to match the common case. It also simplifies the regression and config
scripts to reflect this change.
Instead of relying on derived classes explicitly assigning
to the BasicPioDevice pioSize field, require them to pass
a size value in to the constructor.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
It was confusing having an AmbaDev namespace along with an
AmbaDevice class. The namespace stuff is now moved in to
a new base AmbaDevice class, which is a mixin for classes
AmbaPioDevice (the former AmbaDevice) and AmbaDmaDevice
to provide the readId function as an inherited member function.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
This patch removes the explicit setting of the clock period for
certain instances of CoherentBus, NonCoherentBus and IOCache where the
specified clock is same as the default value of the system clock. As
all the values used are the defaults, there are no performance
changes. There are similar cases where the toL2Bus is set to use the
parent CPU clock which is already the default behaviour.
The main motivation for these simplifications is to ease the
introduction of clock domains.
This patch removes the explicit memset as it is redundant and causes
the simulator to touch the entire space, forcing the host system to
allocate the pages.
Anonymous pages are mapped on the first access, and the page-fault
handler is responsible for zeroing them. Thus, the pages are still
zeroed, but we avoid touching the entire allocated space which enables
us to use much larger memory sizes as long as not all the memory is
actually used.
Previously, nextCycle() could return the *current* cycle if the current tick was
already aligned with the clock edge. This behavior is not only confusing (not
quite what the function name implies), but also caused problems in the
drainResume() function. When exiting/re-entering the sim loop (e.g., to take
checkpoints), the CPUs will drain and resume. Due to the previous behavior of
nextCycle(), the CPU tick events were being rescheduled in the same ticks that
were already processed before draining. This caused divergence from runs that
did not exit/re-entered the sim loop. (Initially a cycle difference, but a
significant impact later on.)
This patch separates out the two behaviors (nextCycle() and clockEdge()),
uses nextCycle() in drainResume, and uses clockEdge() everywhere else.
Nothing (other than name) should change except for the drainResume timing.
Newer core tiles / daughterboards for the Versatile Express platform have an
HDLCD controller that supports HD-quality output. This patch adds an
implementation of the controller.
This patch address the most important name shadowing warnings (as
produced when using gcc/clang with -Wshadow). There are many
locations where constructor parameters and function parameters shadow
local variables, but these are left unchanged.
This patch makes the clock member private to the ClockedObject and
forces all children to access it using clockPeriod(). This makes it
impossible to inadvertently change the clock, and also makes it easier
to transition to a situation where the clock is derived from e.g. a
clock domain, or through a multiplier.
This patch moves the GIC interface to a separate base class and makes
all interrupt devices use that base class instead of a pointer to the
PL390 implementation. This allows us to have multiple GIC
implementations. Future implementations will allow in-kernel GIC
implementations when using hardware virtualization.
--HG--
rename : src/dev/arm/gic.cc => src/dev/arm/gic_pl390.cc
rename : src/dev/arm/gic.hh => src/dev/arm/gic_pl390.hh
This patch removes the intNum and clock from the serialized scalars as
these are set by the Python parameters and should not be part of the
checkpoint.
Fixed check pointing of the framebuffer. Previously, the pixel size was not
considered in determining the size of the buffer to checkpoint. This patch
checkpoints the entire framebuffer instead of the first quarter.
The PL111 model currently maintains a list of pre-allocated
DmaDoneEvents to prevent unnecessary heap allocations. This list
effectively works like a stack where the top element is the latest
scheduled event. When an event triggers, the top pointer is moved down
the stack. This obviously breaks since events usually retire from the
bottom (events don't necessarily have to retire in order), which
triggers the following assertion:
gem5.debug: build/ARM/dev/arm/pl111.cc:460: void Pl111::fillFifo(): \
Assertion `!dmaDoneEvent[dmaPendingNum-1].scheduled()' failed.
This changeset adds a vector listing the currently unused events. This
vector acts like a stack where the an element is popped off the stack
when a new event is needed an pushed on the stack when they trigger.
This patch fixes the Pl111 timings by creating a separate clock for
the pixel timings. The device clock is used for all interactions with
the memory system, just like the AHB clock on the actual module.
The result without this patch is that the module only is allowed to
send one request every tick of the 24MHz clock which causes a huge
backlog.
