Description

We should provide a Virtual Mailbox abstraction on top LwIP, for targets that feature an Ethernet interface but not a NoC.

Related Issues

• [com] Mailboxes

Description

We should add Docker Compose support for the Unix 64-bit target.

Description

• intcl(): controls the behavior of an interrupt

• intwait(): waits for the delivery of an interrupt

• intreturn(): returns from an interrupt handler

• iograb(): allocates an I/O port

• iorelease(): releases an I/O port

• ioread(): reads from an I/O port

• iowrite() writes to an I/O port

• mmiograb(): allocates a memory mapped I/O region

• mmiorelease(): releases a memory mapped I/O region

• mmioread(): reads from an memory mapped I/O region

• mmiowrite(): writes to a memory mapped I/O region`

Description

Currently, whenever we add a new kernel call, we should update NR_SYSCALLS. If we are not cautious, this may introduce a bug in the kernel.

Instead, we should create a constant NR_last_kcall with the last kernel call number and make NR_SYSCALLS expand to it.

Description

We should guard internal symbols of the Microkernel to avoid namespace pollution.

Description

In targets that feature a NoC, we should provide a portal abstraction.

A portal enables processes running on different clusters to exchange airbtraty amounts of data with one another.

Description

We should design new Make rules using Docker Compose to leverage the Nanvix Docker images.

Description

We should add install and uninstall rules to the top-level makefile.

Updates

• Enhancement introduced in commit 214f266.

Description

The OpenCores Ethernet driver does not work with interrupts.

Description

The following testing units for the thread management kernel calls should be designed and implemented:

• API: thread identification (8a257e5)
• API: thread creation/termination (8a257e5)
• Fault Injection: thread creation with invalid starting routine (8a257e5)
• Fault Injection: thread creation with bad starting routine (f0b3d20)
• Fault Injection: thread creation with bad argument (24a05a2)
• Fault Injection: terminate a thread with bad return value (b7acd36)
• Fault Injection: spawn too many threads (8a257e5)
• Fault Injection: join an invalid thread (8a257e5)
• Fault Injection: join a bad thread (8a257e5)
• Fault Injection: join a thread with bad return value (dce8cd5)
• Stress: spawn and join many threads (8a257e5)

Description

The following unit tests for the Page Frame Allocator subsystem should be designed and implemented:

• API Test: Page Frame Address Translation (7392b2b)
• API Test: Page Frame Allocation (7392b2b)
• Fault Injection Test: Invalid* Page Frame Address Translation (7392b2b)
• Fault Injection Test: Invalid* Page Frame Release (7392b2b)
• Fault Injection Test: Bad* Page Frame Release (7392b2b)
• Fault Injection Test: Double Page Frame Release (7392b2b)
• Fault Injection Test: Page Frame Allocation Overflow (7392b2b)
• Stress Test: Page Frame Allocation (7392b2b)

* In Fault Injection Tests, "invalid" means logically not possible and a "bad" semantically not possible.

Description

We should provide a Virtual Portal abstraction on top LwIP, for targets that feature an Ethernet interface but not a NoC.

Related Issues

• [com] Portals

Description

In commit 07086f9 we have disabled TravisCI runs for the Unix 64-bit target. We did so because the following functionalities are somewhat unstable in this target, which in turn cause regression tests to fail too often:

• Overall functioning of mutexes/semaphores
• Spawn and join kernel threads in a tight loop

Description

Introduce compile-time asserts to check if a kernel header is being accidentally included in user code.

Description

We should support optimization flags in a per-target basis.

Updates

• Enhancement Introduced in commit 3ecf529

Description

The following testing units should be designed and implemented for thread synchronization kernel calls:

• API Test: sleep and wakeup (4142783)
• Fault Injection Test: wakeup an invalid thread (4142783)
• Fault Injection Test: wakeup a bad thread (4142783)
• Stress Test: sleep and wakeup many times (4142783)

Related Commits

• Feature: Tests for Thread Synchronization Calls

Description

In commit 0b9778f we have introduced an kernel thread identifier for meaning no thread at all.

We should change the thread system accordingly to make use of this enhancement.

Updates

Enhancement introduced in commit 503956f.

Description

In the contrib/makefile.install we are missing the installation of the LwIP static library.

Description

Currently, we retry thread creation (thread_create()) for an infinite number of times, if the target core is not yet in idle state (core_start() fails with EBUSY).

We should do that only for some time instead, to avoid a kernel lock up.

Description

The following interface should be exported by the kernel so as to enable user-level programs to manipulate the memory.

Functions

• err = pgmap(vaddr, mode): maps a page into memory
• err = pgunmap(vaddr): unmaps a page from memory
• err = pgctl(vaddr, mode): changes features of a page

Description

The following unit tests for assessing the Kernel Calls should be introduced.

API Tests

• Sanity Check Execution Context After a Kernel Call

Fault Injection Tests

• Issue an Invalid Kernel Call
• Issue a Bad Kernel Call
• Issue a Kernel Call from a Bad Execution Context
• Issue a Kernel Call from an Invalid Execution Context

Description

We are currently messing the kernel logs, by using different string formats to log the output. We should stick to a standard formatting for kernel logs, so it becomes easier to debug with automated tools.

Description

We should provide initialization functions for the Sync, Mailbox and Portal interface, so as to enable a dynamic initialization of the HAL.

Roadmap

• MPPA-256
• Unix 64-bit

Related PRs

• #227 - [ikc] Sync Multiplex Bugfix added ksync_init function to initialize the kernel Sync facility.
• #231 - [ikc] Facilities Dynamic Initialization added kportal_init and kmailbox_init to initialize Portal and Mailbox facilities, respectively.

Description

We should support builds for the MPPA-256 in TravisCI.

Updates

• Enhancement introduced in commit b2943ce.

Description

In targets that feature a NoC, we should provide a mailbox abstraction.

A mailbox enables processes running on different clusters to exchange fixed-size messages with one another.

Description

We should introduce the following unit tests to assess the Signal Kernel Calls.

API Tests

• Register and Unregister a Signal Halder (a9e9f2a)
• Trigger a Signal and Handle It

Fault Injection Tests

• Register an Invalid Signal Handler (a9e9f2a)
• Register a Bad Signal Handler

Description

The following interface should be exported by the kernel so as to enable user-level programs to synchronize threads.

Functions

• err = kthread_sleep(): puts the calling thread to sleep
• err = kthread_wakeup(tid): wakes up a thread

Related Commits

• Feature: Thread Synchronization Calls

Description

In targets that feature a NoC, we should provide a synchronization point (sync) abstraction.

A sync enables processes running on different clusters to synchronize their work with one another.

Description

The Kernel Page Pool is a subsystem of the Memory System that maintains a pool of pages for user use. Overall, this subsystem exposes an interface for allocating, releasing mapping and unmapping user pages.

Interface Overview

• upage_alloc(): allocates a user page

• upage_free(): releases a user page

• upage_map(): maps a user page

• upage_unmap(): unmaps a user page

• Feature: User Page Pool

Description

We should provide a Virtual Sync abstraction on top LwIP, for targets that feature an Ethernet interface but not a NoC.

Related Issues

• [com] Syncs

Description

The following unit tests were intentionally disabled, due to unknown issues.

We should track and fix related bugs and then re-enable these tests.

All Targets

• Thread Sleep/Wakeup Stress
• Thread Bad Start
• Thread Bad Argument
• Thread Bad Join
• Thread Stress

Unix 64-bit

• Performance Interface
• Signal Interface

Updates

• Enhancement: Quickly Exit GDB

Description

The Page Frame Allocator is a subsystem of the Memory System that provides a facility for allocating and releasing page frames.

Interface Overview

• frame_alloc(): allocates a page frame
• frame_free(): releases a page frame

Related Commits

• Feature: Page Frame Allocator

Description

If we build the microkernel with sleeping mutexes and semaphores support, we got a lock up in the regression tests.

Description

The following interface should be supported, in order to enable threads to catch, send and manage signals.

Structures

• struct sigaction: describes actions on the receipt of a signal

Functions

• err = alarm(sec): schedules an alarm signal
• err = sigsend(signum, tid): sends a signal
• err = sigwait(signum): waits for the receipt of a signal
• err = sigctl(signum, &sigact): controls the behavior of a signal
• sigreturn(): returns from a signal handler

Roadmap

• sigctl() introduced in commit a9e9f2a.

Description

We should introduce a configuration header for holding build-time parameters of the kernel.

Updates

• Enhancement introduced in commit 5a4a692.

Description

The following unit tests for the User Page Pool subsystem should be designed and implemented:

• API Test: User Page Translation (7392b2b)
• API Test: User Page Allocation (7392b2b)
• API Test: User Page Write (7392b2b)
• Fault Injection Test: Invalid* Kernel Page Allocation (7392b2b)
• Fault Injection Test: Double User Page Allocation (7392b2b)
• Fault Injection Test: Invalid* Kernel Page Release (7392b2b)
• Fault Injection Test: Bad* User Page Release (7392b2b)
• Fault Injection Test: Double User Page Release (7392b2b)
• Fault Injection Test: User Page Allocation Overflow (7392b2b)
• Stress Test: User Page Allocation (7392b2b)
• Stress Test: User Page Write (7392b2b)

* In Fault Injection Tests, "invalid" means logically not possible and a "bad" semantically not possible.

Description

We should move benchmarks out of the source tree.

Updates

• Enhancement instroduced in commit e5947e6.

Description

OpTiMSoC build is failing. We gotta fix this (TravisCI Log)

Description

The following unit tests for the Kernel Page Pool subsystem should be designed and implemented:

• API Test: Kernel Page Translation (7392b2b)
• API Test: Kernel Page Allocation (7392b2b)
• API Test: Kernel Page Write (7392b2b)
• API Test: Kernel Page Clean Allocation (7392b2b)
• Fault Injection Test: Invalid* Kernel Page Release (7392b2b)
• Fault Injection Test: Bad* Kernel Page Release (7392b2b)
• Fault Injection Test: Double Kernel Page Release (7392b2b)
• Fault Injection Test: Kernel Page Allocation Overflow (7392b2b)
• Stress Test: Kernel Page Allocation (7392b2b)
• Stress Test: Kernel Page Write (7392b2b)

* In Fault Injection Tests, "invalid" means logically not possible and a "bad" semantically not possible.

Description

The following interface should be exported by the kernel so as to enable user-level programs to spawn, synchronize and terminate kernel threads.

Types

• kthread_t: used for uniquely identify a kernel thread

Functions

• tid = kthread_self(): returns the identifier of the calling kernel thread
• err = kthread_create(&tid, &start, &args): creates a new kernel thread
• err = kthread_exit(status): terminates the calling kernel thread
• err = kthread_join(tid, &status): waits for a kernel thread to terminate

Related Commits

• Feature: thread_exit() System Call
• Feature: Thread Join Kernel Call
• Bug Fix: Don't Always Block when Joining
• Enhancement: Lock and Flush in Thread Creation
• Feature: Kernel Master Thread
• Bug Fix: Missing Return for Thread Exit
• Enhancement: Check for Bad Thread Start Routine
• Enhancement: Maximum Number of User Threads

Description

Currently kernel threads can be uniquely identified by IDs, but somewhats it is useful to have a logic numbering from 0 to THREAD_MAX to address them.

Indeed, we have been so far using the ID of the core in which the thread is attached to (ie. coreid), but that is ugly.

Description

We should write a driver for the OpenCores Ethernet device (ethoc).

References

• QEMU's OpenRISC Documentation
• QEMU's Opencores Ethernet Device
• Linux's Opencores Ethernet Driver
• OpenCores Ethernet Device Specification

Updates

• Feature introduced in commit 2151838.

Description

We should move the Performance Monitoring interface to user space.

Updates

• Enhancement introduced in commit 0b782e6.

Description

The Memory System should provide handlers for the following exceptions:

• TLB Fault
• Page Fault
• Page Protection

Related Commits

• Feature: Memory Management Exception Handlers
• [hal] Enhancement: Splitting TLB Miss into Data and Instruction
• [hal] Enhancement: Using Physical Address to Retrieve Page Table

Description

The Kernel Page Pool is a subsystem of the Memory System that maintains a pool of pages for kernel use. Overall, this subsystem exposes an interface for allocating and releasing kernel pages, thereby providing the bare-bones for dynamic memory allocation in kernel land.

Interface Overview

• kpage_get(): allocates a kernel page
• kpage_put(): releases a kernel page

Related Commits

• Feature: Kernel Page Pool

Description

Currently, whenever a thread exits it waits on a conditional variable for another thread to join it. The problem however, comes from the fact that there is a single conditional variable for the whole thread system, thus causing all threads that are exiting to be unblocked.

We should fix this problem by introducing a conditional variable for kthread_exit(), for each kernel thread.

Description

We should support release builds in TravisCI.

Updates

• Enhancement introduced in commit d38e330.