This adds functionality to map pages dynamically into kernel virtual
memory. This allows implementing I/O remap for example, which is a useful
(future) feature.
Now, the first target is to support mapping user pages for the kernel.
Why? There are some userspace structures that might be needed when the
userspace process is not running. Semaphores are one such example. Signals
and the WDT timeout both need access to the user semaphore to work
properly. Even though for this only obtaining the kernel addressable
page pool virtual address is needed, for completeness a procedure is
provided to map several pages.
Set the Default CPU bits. The way to use the unset CPU is to call the
sched_setaffinity function to bind a task to the CPU. bit0 means CPU0.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
The spawn proxy thread is a special existence in NuttX, usually some developers
spend a lot of time on stack overflow of spawn proxy thread:
https://github.com/apache/nuttx/issues/9046https://github.com/apache/nuttx/pull/9081
In order to avoid similar issues, this PR will remove spawn proxy thread to simplify
the process of task/posix_spawn().
1. Postpone the related processing of spawn file actions until after task_init()
2. Delete the temporary thread of spawn proxy and related global variables
Signed-off-by: chao an <anchao@xiaomi.com>
because if we pass predefined environment variables table explicitly,
the environment variables created by the board code will be lost.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
it inappropriate to apply volatile to the task list:
1.The code access task list is already protected by critical section
2.The queue is complex struct, it isn't enough to protect by volatile
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
because not all compiler support the weak attribute, and
many features are either always used or guarded by config.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
If address environments are in use, it is not possible to simply
memcpy from from one process to another. The current implementation
of env_dup does precisely this and thus, it fails at once when it is
attempted between two user processes.
The solution is to use the kernel's heap as an intermediate buffer.
This is a simple, effective and common way to do a fork().
Obviously this is not needed for kernel processes.
- User mode allocator was used for setting up the environment. This
works in flat mode and probably in protected mode as well, as there
is always a a single user allocator present
- This does not work in kernel mode, where each user task has its own
heap allocator. Also, when the idle tasks environment is being set,
no allocator is ready and the system crashes at once.
Fix this by using the group allocators instead:
- Idle task is a kernel task, so its group is privileged
- Add group_realloc
- Use the group_malloc/realloc functions instead of kumm_malloc
argv is allocated from stack and then belong to userspace,
so task_info_s is a best location to hold this information.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
