After activating the client page tables the client context cannot be
accessed any longer. The mode transition buffer however is globally
mapped and can be used to restore the remaining register values.
Set the stack pointer to the R8 field in the client context to enable
restoring registers by popping values of the stack.
After this step the only remaining registers that do not contain client
values are RAX, RSP and RIP.
Note that the client value of RAX is pop'd to the global buffer region as
the register will still be used by subsequent steps. It will be restored to
the value in the buffer area just prior to resuming client code execution.
Set I/O privilege level to 3 to allow core to perform port I/O from
userspace. Also make sure the IF flag is cleared for now until interrupt
handling is implemented.
Setup an IA-32e interrupt stack frame in the mode transition buffer region.
It will be used to perform the mode switch to userspace using the iret
instruction.
For detailed information about the IA-32e interrupt stack frame refer to
Intel SDM Vol. 3A, figure 6-8.
The constants specify offset values of CPU context member variables as
specified by Genode::Cpu_state [1] and Genode::Cpu::Context [2].
[1] - repos/base/include/x86_64/cpu/cpu_state.h
[2] - repos/base-hw/src/core/include/spec/x86/cpu.h
The new entries specify a 64-bit code segment with DPL 3 at index 3 and a
64-bit data segment with DPL 3 at index 4.
These segments are needed for transitioning to user mode.
A pointer to the client context is placed in the mt_client_context_ptr area.
It is used to pass the current client context to the lowlevel mode-switching
assembly code.
IA-32e paging translates 48-bit linear addresses to 52-bit physical
addresses. Translation structures are hierarchical and four levels deep.
The current implementation supports regular 4KB and 1 GB and 2 MB large
page mappings.
Memory typing is not yet implemented since the encoded type bits depend
on the active page attribute table (PAT)*.
For detailed information refer to Intel SDM Vol. 3A, section 4.5.
* The default PAT after power up does not allow the encoding of the
write-combining memory type, see Intel SDM Vol. 3A, section 11.12.4.
* Add common IA-32e paging descriptor type:
The type represents a table entry and encompasses all fields shared by
paging structure entries of all four levels (PML4, PDPT, PD and PT).
* Simplify PT entry type by using common descriptor:
Differing fields are the physical address, the global flag and the memory
type flags.
* Simplify directory entry type by using common descriptor:
Page directory entries (PDPT and PD) have an additional 'page size' field
that specifies if the entry references a next level paging structure or
represents a large page mapping.
* Simplify PML4 entry type by using common descriptor
Top-level paging structure entries (PML4) do not have a 'pat' flag and the
memory type is specified by the 'pwt' and 'pcd' fields only.
* Implement access right merging for directory paging entries
The access rights for translations are determined by the U/S, R/W and XD
flags. Paging structure entries that reference other tables must provide
the superset of rights required for all entries of the referenced table.
Thus merge access rights of new mappings into existing directory entries to
grant additional rights if needed.
* Add cr3 register definition:
The control register 3 is used to set the current page-directory base
register.
* Add cr3 variable to x86_64 Cpu Context
The variable designates the address of the top-level paging structure.
* Return current cr3 value as translation table base
* Set context cr3 value on translation table assignment
* Implement switch to virtual mode in kernel
Activate translation table in init_virt_kernel function by updating the
cr3 register.
* Ignore accessed and dirty flags when comparing existing table entries
These flags can be set by the MMU and must be disregarded.
* Add isr.s assembler file:
The file declares an array of Interrupt Service Routines (ISR) to handle
the exception vectors from 0 to 19, see Intel SDM Vol. 3A, section
6.3.1.
* Add Idt class:
* The class Genode::Idt represents an Interrupt Descriptor Table as
specified by Intel SDM Vol. 3A, section 6.10.
* The setup function initializes the IDT with 20 entries using the ISR
array defined in the isr.s assembly file.
* Setup and load IDT in Genode::Cpu ctor:
The Idt::setup function is only executed once on the BSP.
* Declare ISRs for interrupts 20-255
* Set IDT size to 256
This patch contains the initial code needed to build and bootstrap the
base-hw kernel on x86 64-bit platforms. It gets stuck earlier
because the binary contains 64-bit instructions, but it is started in
32-bit mode. The initial setup of page tables and switch to long mode is
still missing from the crt0 code.
A Nic::Session client can install a signal handler that is used to
propagate changes of the link-state by calling 'link_state_sigh()'.
The actual link state is queried via 'link_state()'.
The nic-driver interface now provides a Driver_notification callback,
which is used to forward link-state changes from the driver to the
Nic::Session_component.
The following drivers now provide real link state: dde_ipxe, nic_bridge,
and usb_drv. Currently, OpenVPN, Linux nic_drv, and lan9118 do not
support link state and always report link up.
Fixes#1327
If a client acknowledges the same packet more than once, the packet also
gets freed more than once. At the second attempt the underlaying
Bit_array will throw an 'Invalid_clear' exception, which results in an
uncaught exception that leads to an abort() call in the freeing
component.
Fixes#1462.
To ease debugging without the need to tweak the kernel every time, and to
support userland developers with useful information this commit extends several
warnings and errors printed by the kernel/core by which thread/application
caused the problem, and what exactly failed.
Fix#1382Fix#1406
The driver for the Freescale eSDHCv2 doesn't support the highest
available bus frequency by now and also the bus width may be set to a
higher value but that needs further checks on the capabilities of the
inserted card.
The commits provide a benchmark as it exists for the OMAP4 SDHC driver.
Fix#1458
The 'continue_hw_accelerated' assertion at the end of the recall handler
can fail in situations which are not problematic, for example if the
'Timer' thread has set the 'VMCPU_FF_TIMER' flag in the meantime and
requested a recall afterwards. Since we don't know for sure if a recall is
requested for the other flags as well, the assertion gets replaced by a
debug message, which gets printed if any of the 'not yet verified as safe'
flags is set.
Fixes#1426
The GUID partition table (GPT) is primarily used by systems using
(U)EFI and is a replacement for the legacy MBR. For now, the current
implementation is able to address up to 128 GUID partition entries
(GPE).
To enable the GPT support in 'part_blk' it has to be configured
accrodingly:
! <start name="part_blk">
! [...]
! <config use_gpt="yes">
! [...]
! </start>
If 'part_blk' is not able to find a valid GPT header it falls back
to using the MBR.
Current limitations:
Since no endian conversion takes place it only works on LE platforms
and of all characters in the UTF-16 encoded name field of an entry
only the ones included in the ASCII encoding are printed. It also
ignores all GPE attributes.
Issue #1429.
The hover reports provides information about the session currently
pointed-to, i.e., hovered session. It can be enabled by the 'hover'
attribute of nitpicker's 'report' configuration element
<report hover="yes" />
Fixes#1442
The bindings for 32bit did not consider that in the syscall_3 function
edx changes due to the assembly instructions and that in the syscall_4
function edx and ecx change. So, the compiler wrongly assumed that the
content of these registers stayed unchanged.
Fixes#1447
In the past, unmap sometimes occured on RM clients that have no thread,
PD, or translation table assigned. However, this shouldn't be the
case anymore.
Fixes#504
* Introduce hw-specific crt0 for core that calls e.g.: init_main_thread
* re-map core's main thread UTCB to fit the right context area location
* switch core's main thread's stack to fit the right context area location
Fix#1440
This decouples the size of the mode transition control region from the
minimal mapping size of the page tables implementation. Rather, the CPU
architecture is able to specify the actual size.
Rationale: For x86_64, we need the mtc region to span two pages in order
to store all the tables required to perform the mode switch.
The size of empty structs differs in C (0 byte) and C++ (1 byte), which
leads to different offsets in compound structures. This fixes the driver
on 32Bit platforms.
Issue #1439.
The wireless stack calls timer_before(foo, timer.expires) and up to now
it was always 0. Let's be save and set this field when scheduling the
timer, although it worked fine so far.
Issue #1439.
We will always see this error message when the driver is started. It
is expected and not an actual error. When the driver is running it will
not allocate larger chunks than the Slab provides. Therefore, we can
safely ignore this message.
Issue #1439.
Some functions in the time manager, for example 'TMTimerSet()' and
'TMTimerStop()' let VirtualBox abort with a failed assertion if the timer
does not change to a 'stable' state after 1000 calls of a mixture of
'yield' and 'sleep'. On Genode, this happens sometimes when the 'EMT'
thread is executing 'TMTimerSet()' and gets interrupted by the 'TAP'
thread, which calls 'TMTimerStop()' and waits for the 'EMT' thread to
finish setting the timer. Since the 'EMT' thread has the lowest priority,
1000 retries can be too few. Without the assertion, these functions would
return an error code, which is often ignored by the caller, so it seems
safer to keep retrying until the function can return successfully.
Fixes#1437
Among others, this function is used in the for_each_set_big() macro,
which is used when configuring the data rate tables. Therefore, this
fixes observed performance issues.
Fixes#1439.
If running multiple VBox VMMs with Windows as guest concurrently then it may
happen that the system seem to hang. It turned out that actually
a VM-exit storm (vmx_exception->handle_exc_nm) causes a endless loop between
kernel and vCPU. Nothing gets scheduled nor interrupts are received anymore.
The referenced kernel commit fixes this issue.
Issue #1343
Drivers like SD-Card, platform, AHCI, and framebuffer are specified as Exynos5
compliant. But they are at least not compliant with Odroid-XU although this is
Exynos5. Thus, prevent tests that rely on such drivers when building for
hw_odoid_xu. Furthermore, make previous Arndale regulator/consts.h,
uart_defs.h, and some Board_base enums available to all Exynos5 builds to
enable at least building the drivers.
Fixes#1419
For the USB-Armory, we use a newer version of Linux (3.18) as for the
i.MX53-QSB. The main difference is, that the newer Linux uses a DTB instead of
ATAGs.
Fixes#1422
The USB Armory is almost the same as the i.MX53-QSB but it uses only
one of the two RAM banks available in i.MX53. Furthermore we use the USB
Armory only with Trustzone enabled.
Ref #1422
With the new run tool, there is no more is_qemu_available function. However,
some scripts still try to use it because only frequently used scripts were
updated by now. The commit replaces the function calls with the new
'have_include power_on/qemu' check.
Ref #1419
The wifi_drv now provides two reports. The first one contains all
accesspoints that were found while scanning the supported frequencies.
The second one reports the state of the driver, i.e., if it is
conntected to an accesspoint or not. In addition to that, the driver
now gets its configuration via a ROM session.
More detailed information are available in 'repos/dde_linux/README'.
Issue #1415.
* enables world-switch using ARM virtualization extensions
* split TrustZone and virtualization extensions hardly from platforms,
where it is not used
* extend 'Vm_session' interface to enable configuration of guest-physical memory
* introduce VM destruction syscall
* add virtual machine monitor for hw_arndale that emulates a simplified version
of ARM's Versatile Express Cortex A15 board for a Linux guest OS
Fixes#1405
To enable support of hardware virtualization for ARM on the Arndale board,
the cpu needs to be prepared to enter the non-secure mode, as long as it does
not already run in it. Therefore, especially the interrupt controller and
some TrustZone specific system registers need to be prepared. Moreover,
the exception vector for the hypervisor needs to be set up properly, before
booting normally in the supervisor mode of the non-secure world.
Ref #1405
To enable the usage of virtualization extension related instructions
there is the need to enable the '-mcpu=cortex_a15' compiler flag on
those cpus. To not conflict with other compiler flags (Ref #810) we've
to disable the '-march=arm_v7a' flag.
Ref #1405
The generalization of interrupt objects in the kernel and the use of
C++ polymorphism instead of explicitely checking for special interrupts
within generic code (Cpu_job::_interrupt) enables the registration of
additional interrupts used by the kernel, which are needed for specific
aspects added to the kernel, like ARM hardware virtualization interrupts.
* Introduce generic base class for interrupt objects handled by the kernel
* Derive an interrupt class for those handled by the user-land
* Implement IPI-specific interrupt class
* Implement timer interrupts using the new generic base class
Ref #1405
Until now, one distinct software generated IRQ per cpu was used to
send signals between cpus. As ARM's GIC has 16 software generated
IRQs only, and they need to be partitioned between secure/non-secure
TrustZone world as well as virtual and non-virtual worlds, we should
save them.
Ref #1405
* name irq controller memory mapped I/O regions consistently
in board descriptions
* move irq controller and timer memory mapped I/O region descriptions
from cpu class to board class
* eliminate artificial distinction between flavors of ARM's GIC
* factor cpu local initialization out of ARM's GIC interface description,
which is needed if the GIC is initialized differently e.g. for TrustZone
Ref #1405
The 'dest' target is renamed in the updated rump version to 'dest.stage'. This
triggered some building steps, even when the targets already existed.
Issue #1409
The handling of MMIO regions now supports more pathological cases with
weird cross references. Also, MMIO regions are releases after the
parsing is done.
Fixes#998
Setting the ACTLR.SMP bit also without SMP support fastens RAM access
significantly. A proper solution would implement SMP support which must enable
the bit anyway.
Fixes#1353
When returning early on directory operations, file systems that might
be able to handle the request but come after the current one are not
tried.
Fixes#1400.
Up to now Noux used the libc sleep functions, which actually is not
possible because the _nanosleep() function implemented by our libc
creates a new thread to handle the timeout. Noux childs may have
only one thread, e.g., the main thread, though. To fix this issue
sleeping is now handled directly by Noux. It is implemented by calling
select(2) with a timeout. This fix is needed for mutt(1), which calls
sleep when it prints a notification for the user.
Fixes#1374.
Since rump now requires large buffers of random numbers (>= 512 bytes), use the
jitterentropy library instead of the slow timer pseudo random number generation.
Fixes#1393
To circumvent compilation errors with the older L4Android Linux kernel
version, the ballooning driver is included in the more recent L4Linux
kernel only. Moreover, to be able to maintain L4Android / L4Linux in a more
convenient way, e.g. to apply patches valid for both versions, we use
the same git clone that is used for L4Linux instead of using the upstream
L4Android version by applying patches.
Fixes#1390
Instead of returning an uint64_t value, return a structured time stamp.
This change is only visible to components using Rtc_session directly.
Fixes#1381.
Up until now 'schedule_timeout' did only wait for the next signal to occur.
However, we might run into situations where there won't occur signals for longer
periods of time. Therefore, we took care of the respective timeout handling.
This commit also adds Genode's tracing support
Issue #1310
This has been broken for a while now. Use correct (global) signal transmission,
do not use local signal transmission, as signals seems to get lost.
Issue #1310
This patch changes the Shared_object::lookup function to use a
reinterpret_cast instead of a static_cast to allow the conversion
from symbol addresses to arbitrary pointers.
By blocking on a timeout, we yield the CPU in order to give a
concurrently running sporadic process a chance to obtain ROM modules.
Otherwise, such requests would be deferred until the ROM prefetcher
completes its operation or in the unlikely event that the prefetcher
gets preempted.
Fixes#1378
The linker scripts use to fill alignment gaps within the text section
with the magic value 0x90909090, which correponds to the opcodes of four
nop instructions on x86. This patch removes this value because it
apparently solves no problem. If, for some reason (e.g., due to a dangling
pointer) a thread executes instructions within alignment paddings, NOP
instructions are not any better than any other instruction. The program
will eventually execute the instructions after the padding, which is
most likely fatal. It would be more reasonable to fill the padding with
the opcode of an illegal instruction so that such an error can be
immediately detected. That said, I cannot remember a single instance,
where the fill value has helped us during debugging.
Even if the mechanism served a purpose on x86, it is still better to
remove it because it does not equally work on the other architectures
where the linker scripts are used. I.e., on ARM, the opcode 0x90909090
is not a NOP instruction.
If newlines are in the string send to the core log service, they don't get
the label properly appended before each output. The messages then look like
they are coming from core.
Fixes#1368
Be less verbose regards warnings caused by vmx_invalid exits - which triggers
on T400 more often because it has no Unrestricted Guest support. This leads
to lot of log messages so that the test does not succeed in time. Additionally,
the virtualbox_auto_disk.run script is adjusted to check for some output to
exit earlier if something went wrong.
Fixes#1367
Workaround for issue #1343. By disabling the 'vpid' feature of the nova
kernel several VMs can be used concurrently. Applies for Seoul and VirtualBox.
Issue #1343
Instead of fixing the missing dynamic facilities of the AHCI driver
backends for x86 and Exynos5, just avoid to create/destroy the backend
for every new connection, but always use one and the same object.
The AHCI drivers need to be re-written anyway, see issue #1352 for instance,
we can make it more robust for the dynamic case then.
Fixes#786Fixes#1133
This has to be used during shared object creation and destruction because global
lists are manipulated. We cannot use the 'Elf_object::lock' here because there
may be jump-slot relocations during object initialization.
Fixes#1350
When building Genode for VEA9X4 as micro-hypervisor protected by the ARM
TrustZone hardware we ran into limitations regarding our basic daily
testing routines. The most significant is that, when speaking about RAM
partitioning, the only available options are to configure the whole SRAM
to be secure and the whole DDR-RAM to be non-secure or vice versa. The
SRAM however provides only 32 MB which isn't enough for both a
representative non-secure guest OS or a secure Genode that is still
capable of passing our basic tests. This initiated our decision to
remove the VEA9X4 TrustZone-support.
Fixes#1351
On VEA9X4-TZ, the context-area overlaps with the virtual area of the
text, data and bss. However, we can't simply change the link address as
the core image (used physically respectively 1:1 mapped) needs to be in
this particular RAM-region as it is the only one that can be protected
against a VM. Thus I've moved the context area to a place where it
shouldn't disturb any HW-platform.
Fixes#1337
Declaring the SP804 0/1 module and its interrupt to be non-secure prevents the
secure Genode from receiving the interrupt and hence the timer driver in the
secure Genode doesn't work.
Fixes#1340
The commit uses a fixed kernel branch (r8), which fixes a caching bug
observable in the Genode host. The quirk detecting the circumstance in the
timer service is obsolete now and is removed.
Fixes#1338
The commit
- fixes the syscall bindings for using portal permissions
- revokes PT_CTRL permission after pager in core set local badge name
- revokes PT_CTRL permission after server entrypoint code set local badge name
Fixes#1335
This fix configures TTBRs and translation-table descriptors as if we would use
SMP although we don't to circumvent problems with UP-configurations.
This fix should be superseded later by full SMP support for the VEA9X4.
ref #1312
The HW-kernel, in contrast to other kernels, provides a direct reference
to the pager object with the fault signal that is send to the pager
activation. When accessing this reference directly we may fall into the
time span where the root parent-entrypoint of the faulter has alredy
dissolved the pager object from the pager entrypoint, but not yet
silenced the according signal context. To avoid this we issue an
additional 'lookup_and_lock' with the received pager object. This isn't
optimal as we don't need the potentially cost-intensive lookup but only the
synchronization.
Fixes#1311.
Fixes#1332.
- essential support for 7260 chipset and DMA fixes
- assign mvm->pm_ops at beginning of function iwl_op_mode_mvm_start.
iwl_mvm_mac_setup_register() uses mvm->pm_ops, but it is called
before this field is set to a valid value.
- disable call to function iwl_mvm_prepare_multicast.
This function leads to a pagefault, as it aspects a list of multicast
addresses, but the list is empty as it is not generated by this port.
On base-hw, each thread owns exactly one scheduling context for its
whole lifetime. However, introducing helping on IPC, a thread might get
executed on scheduling contexts that it doesn't own. Figuratively
spoken, the IPC-helping relation spans trees between threads. These
trees are identical to those of the IPC relation between threads. The
root of such a tree is executed on all scheduling contexts in the tree.
All other threads in the tree are not executed on any scheduling context
as long as they remain in this position. Consequently, the ready-state
of all scheduling contexts in an IPC-helping tree always equals the
state of the root context.
fix#1102
As soon as helping is used, a thread may also be in a blocking state when its
scheduling context is ready. Hence, the state designation SCHEDULED for an active
thread would be pretty misleading.
ref #1102
If the debug branch of the nova kernel is used, following messages are printed
by the kernel during vCPU setup phase:
[0] overmap attempt OBJ - tree - ...
Fixes#1324
The context of timer are now inserted correctly and the actual timer
triggering the exection of each context is always programmed if the
head of the timer list changes.
Fixes#1326.
The jiffies are only updated on each round of scheduling the runnable
tasks. We have to schedule the current task that executes the sleep
call to update the jiffies count and thereby preventing the task from
entering an endless loop when using a statement like
'while (!time_after(jiffies, now + timeout)) { msleep(1); }'.
Related to #1326.
Instead of probing all device on the PCI bus just look for devices
matching PCI_CLASS_NETWORK_OTHER. This fixes issues with other devices
on the PCI bus, e.g. the GPU, when access their extended config space.
Related to #1326.
Setting explicit routes for Nitpicker's 'Framebuffer' and 'Input' sessionsi
avoids ambiguities if a Qt application provides these services, too.
Fixes#1316
With this patch, when calling 'setFocus()' on a QNitpickerViewWidget, the
Nitpicker view gets the input focus (provided that the parent Qt window
already had it).
Fixes#1314
Until now, the successful termination of the boot process was recognized
when 'expect' saw the first L4 bootstrapper output on serial line. On sytems
with initially shaky serial connection like Versatile Express, where the serial
line baudrate changes with the bootstrapper initialization, the first expected
line might be missing. Therefore, change the expected line to the first
Fiasco.OC kernel output.
This wasn't necessary before because we built an l4 library for
Pistachio and linked it against each application. With the new linker,
we compile the required files from within Genode and create a syscall
library that is only linked to ldso. If a program uses system calls
directly, for example, DDE kit's spinlock implementation, the required
symbols must be made globally accessible.
Fixes#1306
On the Versatile Express Cortex A9x4 platform the first memory region
0x0 - 0x4000000 is a hardware remapped memory area, containing flash
and DDR RAM copies and thus should not be added in addition to all
DDR RAM regions and the SRAM region.
In the init configuration one can configure the donation of CPU time via
'resource' tags that have the attribute 'name' set to "CPU" and the
attribute 'quantum' set to the percentage of CPU quota that init shall
donate. The pattern is the same as when donating RAM quota.
! <start name="test">
! <resource name="CPU" quantum="75"/>
! </start>
This would cause init to try donating 75% of its CPU quota to the child
"test". Init and core do not preserve CPU quota for their own
requirements by default as it is done with RAM quota.
The CPU quota that a process owns can be applied through the thread
constructor. The constructor has been enhanced by an argument that
indicates the percentage of the programs CPU quota that shall be granted
to the new thread. So 'Thread(33, "test")' would cause the backing CPU
session to try to grant 33% of the programs CPU quota to the thread
"test". By now, the CPU quota of a thread can't be altered after
construction. Constructing a thread with CPU quota 0 doesn't mean the
thread gets never scheduled but that the thread has no guaranty to receive
CPU time. Such threads have to live with excess CPU time.
Threads that already existed in the official repositories of Genode were
adapted in the way that they receive a quota of 0.
This commit also provides a run test 'cpu_quota' in base-hw (the only
kernel that applies the CPU-quota scheme currently). The test basically
runs three threads with different physical CPU quota. The threads simply
count for 30 seconds each and the test then checks wether the counter
values relate to the CPU-quota distribution.
fix#1275
Do not support the global construction from of objects from within a global
constructor of another object. This can happen if, for example, dlopen is called
from a global constructor. The construction will be post-boned until the current
constructor has finished.
On Arndale, the kernel timer resets to the initial value of the last
count-down and continues as soon as it reaches zero. We must check this
via the interrupt status when we read out the timer value and in case
return 0 instead of the real value.
fix#1299
The way this function is currently used in dde_linux expects this
function to return. Since there is dde_kit_panic it should better
be used in such a case the output should block.
Kernel::Processor was a confusing remnant from the old scheme where we had a
Processor_driver (now Genode::Cpu) and a Processor (now Kernel::Cpu).
This commit also updates the in-code documentation and the variable and
function naming accordingly.
fix#1274
The run test 'hw_info' prints the content of the basic ARMv7 identification and
feature registers in a pretty readable format. It is a kernel-internal test
because many of these registers are restricted to privilege level 1 or higher.
fix#1278
The new scheduler serves the orthogonal requirements of both
high-throughput-oriented scheduling contexts (shortly called fill in the
scheduler) and low-latency-oriented scheduling contexts (shortly called
claim in the scheduler). Thus it knows two scheduling modes. Every claim
owns a CPU-time-quota expressed as percentage of a super period
(currently 1 second) and a priority that is absolute as long as the
claim has quota left for the current super period. At the end of a super
period the quota of all claims gets refreshed. During a super period,
the claim mode is dominant as long as any active claim has quota left.
Every time this isn't the case, the scheduler switches to scheduling of
fills. Fills are scheduled in a simple round robin with identical time
slices. Order and time-slices of the fill scheduling are not affected by
the super period. Now on thread creation, two arguments, priority and
quota are needed. If quota is 0, the new thread participates in CPU
scheduling with a fill only. Otherwise he participates with both a
claim and a fill. This concept dovetails nicely with Genodes quota based
resource management as any process can grant subsets of its own
CPU-time and priorities to its child without knowing the global means of
CPU-time and priority.
The commit also adds a run script that enables an automated unit test of the
scheduler implementation.
fix#1225
To serve the needs of the coming CPU scheduler, the double list needs
additional methods such as 'to_tail' and 'insert_head'.
The commit also adds a run script that enables an automated unit test
of the list implementation.
ref #1225
Kernel tests are done by replacing the implementation of an otherwise
empty function 'Kernel::test' that gets called once at the primary CPU
as soon as all kernel initialization is done. To achieve this, the test
binary that implements 'Kernel::test' must be linked against the core
lib and must then replace the core binary when composing the boot image.
The latter can be done conveniently in a run script by setting the new
argument 'core_type' of the function 'build_boot_image' to the falue
'test'. If no kernel test is needed the argument does not have to be
given - it is set to 'core' by default which results in a "normal"
Genode image.
ref #1225
Previously, Idle_thread inherited from Thread which caused an extra
processor_pool.h and processor_pool.cc and also made class models for
processor and scheduling more complex. However, this inheritance makes
not much sense anyway as an idle context doesn't trigger most of the code
in Thread.
ref #1225
The memory barrier prevents the compiler from changing the program order
of memory accesses in such a way that accesses to the guarded resource
get outside the guarded stage. As cmpxchg() defines the start of the
guarded stage it also represents an effective memory barrier.
On x86, the architecture ensures to not reorder writes with older reads,
writes to memory with other writes (except in cases that are not
relevant for our locks), or read/write instructions with I/O
instructions, locked instructions, and serializing instructions.
However on ARM, the architectural memory model allows not only that
memory accesses take local effect in another order as their program
order but also that different observers (components that can access
memory like data-busses, TLBs and branch predictors) observe these
effects each in another order. Thus, a correct program order isn't
sufficient for a correct observation order. An additional architectural
preservation of the memory barrier is needed to achieve this.
Fixes#692
GCC 4.7.4 and newer seems to optimize the lock-variable accesses more
radically, which uncovered the missing volatile qualifier and resulted
in:
Assertion "(int)locked >= 0" failed in file '.../okl4_x86/kernel/include/kernel/read_write_lock.h', line 151 (fn=f0104771)
--- "KD# assert" ---
Invalidating all branch predictors before switching the PD
fixes instability problems on Panda and has not much effect
on the performance of other boards. However, we neither know why
this is a fix nor wether it fixes the real cause of the problem.
fix#1294
Previously, the timer was used to remember the state of the time slices.
This was sufficient before priorities entered the scene as a thread always
received a fresh time slice when he was scheduled away. However, with
priorities this isn't always the case. A thread can be preempted by another
thread due to a higher priority. In this case the low-priority thread must
remember how much time he has consumed from its current time slice because
the timer gets re-programmed. Otherwise, if we have high-priority threads
that block and unblock with high frequency, the head of the next lower
priority would start with a fresh time slice all the time and is never
superseded.
fix#1287
Some SDL applications expect the SDL_image headers in include/SDL to be
reachable without the SDL/ prefix. This patch adds the corresponding
search path. Furthermore it enables support for XPM images.
Ported drivers list and extract all needed source files. This decouples
ports according to contrib sources and also enables us to revert lxip to
Linux version 3.9, while staying with 3.14 for usb.
Fixes#1285
The manpage to errno tells the following story:
The <errno.h> header file defines the integer variable errno, which is
set by system calls and some library functions in the event of an error
to indicate what went wrong. Its value is significant only when the
return value of the call indicated an error (i.e., -1 from most system
calls; -1 or NULL from most library functions); a function that
succeeds is allowed to change errno.
Valid error numbers are all nonzero; errno is never set to zero by any
system call or library function.
When the 'Mtd::FPU' flag is set during the registration of a
virtualization event handler, it must also be set whenever the event
handler returns.
Fixes#1283
This patch ensures that priority values passed as session arguments
are within the valid range of priorities. Without the clamping, a child
could specify a priority of a lower priority band than the one assigned
to the subsystem. Thanks to Johannes Schlatow for reporting this issue.
Fixes#1279
This is just a quick fix to calm down the buildbot - a revised
implementation is needed according to issue #1277. Further, the reason
for the increased test duration on several platforms must be
investigated.
