There is currently a big problem in the address environment handling which
is that the address environment is released too soon when the process is
exiting. The current MMU mappings will always be the exiting process's, which means
the system needs them AT LEAST until the next context switch happens. If
the next thread is a kernel thread, the address environment is needed for
longer.
Kernel threads "lend" the address environment of the previous user process.
This is beneficial in two ways:
- The kernel processes do not need an allocated address environment
- When a context switch happens from user -> kernel or kernel -> kernel,
the TLB does not need to be flushed. This must be done only when
changing to a different user address environment.
Another issue is when a new process is created; the address environment
of the new process must be temporarily instantiated by up_addrenv_select().
However, the system scheduler does not know that the process has a different
address environment to its own and when / if a context restore happens, the
wrong MMU page directory is restored and the process will either crash or
do something horribly wrong.
The following changes are needed to fix the issues:
- Add mm_curr which is the current address environment of the process
- Add a reference counter to safeguard the address environment
- Whenever an address environment is mapped to MMU, its reference counter
is incremented
- Whenever and address environment is unmapped from MMU, its reference
counter is decremented, and tested. If no more references -> drop the
address environment and release the memory as well
- To limit the context switch delay, the address environment is freed in
a separate low priority clean-up thread (LPWORK)
- When a process temporarily instantiates another process's address
environment, the scheduler will now know of this and will restore the
correct mappings to MMU
Why is this not causing more noticeable issues ? The problem only happens
under the aforementioned special conditions, and if a context switch or
IRQ occurs during this time.
PWM driver for multiple peripherals supplied in gateware.
Only single channel frequency and duty cycle control is implemented. Pulse counting and multichannel features are not currently feasible.
Additions also include a new board configuration for arty-a7 which enables the PWM driver and example application.
MCUboot support is no longer behind EXPERIMENTAL for the following
chips:
- ESP32
- ESP32-S2
- ESP32-S3
- ESP32-C3
Signed-off-by: Gustavo Henrique Nihei <gustavo.nihei@espressif.com>
Summary:
- This commit adds knetnsh64 and knetnsh64_smp
Impact:
- None
Testing:
- Tested with ping, telnet and iperf on QEMU-7.1
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Summary:
- This commit fixes the CI build errors regressed by
https://github.com/apache/incubator-nuttx/pull/7351
Impact:
- None
Testing:
- Build only
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Currently the IHC (Inter Hart Communication) depends on OpenAMP and
rptun. However, the bootloader portion of the IHC doesn't need
either of them. Now they are wasting a lot of bootloader space.
Reorganize the bootloader portion into a separate file 'mpfs_ihc_sbi.c'.
This file contains the OpenSBI vendor extensions, or the only required
functionalities for the bootloader. On the other hand, 'mpfs_ihc.c'
contains the non-bootloader code.
This patch also makes it possible to utilize 2 RPMSG channels. This
has been tested so that 2 separate NuttXs on harts 1 and 2 communicate
with Linux kernel that runs on harts 3 and 4.
New configuration files are added as well:
- rpmsg-ch1: sample config for RPMSG
- rpmsg-ch2: sample config for another RPMSG channel
- rpmsg-sbi: sample bootloader config for RPMSG/OpenSBI
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
Alan Carvalho de Assis