Brennan Ashton 46b0f6d6ee fdt: Add initial FDT support and procfs for userspace export
VELAPLATFO-12536

This provides the initial hooks for Flattened Device Tree support
with QEMU RV. It also provides a new procfs file that exposes the
fdt to userspace much like the /sys/firmware/fdt endpoint in Linux.
See https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw

Nodes in the fdt are not yet usable by the OS.

Signed-off-by: Brennan Ashton <bashton@brennanashton.com>
Signed-off-by: liaoao <liaoao@xiaomi.com>
2023-08-05 12:41:06 -07:00
..
2023-05-27 03:29:41 +08:00
2023-05-27 03:29:41 +08:00
2023-02-24 12:15:40 +08:00

fs/procfs README
================

  This is a tiny procfs file system that allows read-only access to a few
  attributes of a task or thread.  This tiny procfs fs file system can be
  built into the system by enabling:

    CONFIG_FS_PROCFS=y

  It can then be mounted from the NSH command like like:

    nsh> mount -t procfs /proc

Example
=======

  NuttShell (NSH) NuttX-6.31
  nsh> mount -t procfs /proc

  nsh> ls /proc
  /proc:
   0/
   1/

  nsh> ls /proc/1
  /proc/1:
   status
   cmdline

  nsh> cat /proc/1/status
  Name:       init
  Type:       Task
  State:      Running
  Priority:   100
  Scheduler:  SCHED_FIFO
  SigMask:    00000000

  nsh> cat /proc/1/cmdline
  init

  nsh> sleep 100 &
  sleep [2:100]
  nsh> ls /proc
  ls /proc
  /proc:
   0/
   1/
   2/

  nsh> cat /proc/2/cmdline
  <pthread> 0x527420