reorganize debug comments
cleanup pending status at boot

I had the problem that the transmit FIFO size (= actual elements in FIFO) was slowly increasing over time, and was full after a few hours.

The reason was that the code hit the line "canerr("ERROR: No available mailbox\n");" in stm32_cansend, so can_xmit thinks it has sent the packet to the hardware, but actually has not. Therefore the transmit interrupt never happens which would call can_txdone, and so the size of the FIFO size does not decrease.

The reason why the code actually hit the mentioned line above, is because stm32can_txready uses a different (incomplete) condition than stm32can_send to determine if the mailbox can be used for sending, and thus can_xmit forwards the packet to stm32can_send. stm32can_txready considered mailboxes OK for sending if the mailbox was empty, but did not consider that mailboxes may not yet be used if the request completed bit is set - stm32can_txinterrupt has to process these mailboxes first.

Note that I have also modified stm32can_txinterrupt - I removed the if condition, because the CAN controller retries to send the packet until it succeeds. Also if the condition would not evaluate to true, can_txdone would not be called and the FIFO size would not decrease also.

implement get_chip_status and use it to detect command errors

Ieee802154

Approved-by: Gregory Nutt <gnutt@nuttx.org>

photon/wlan: disable network logs and add nsh over telnet

Approved-by: Gregory Nutt <gnutt@nuttx.org>

TCP: Fix some potential error conditions that could result from deferring the connection until the full 3-way handshake has completed.

Syslog interrrupt buffer:  eliminate a warning about an uninitialized variable; simply some related logic.

libc/wchar: Versions mbrlen and mbsrtowcs taken and adapted from FreeBSD code (at https://github.com/freebsd/freebsd/)

libc/wchar: Versions mbrlen and mbsrtowcs taken and adapted from FreeBSD code (at https://github.com/freebsd/freebsd/)

Kconfig/deconfigs:  Add CONFIG_ARCH_TOOLCHAIN_GNU to indicate that the toolchain is based on GNU gcc/as/ld.  This is in addition to the CPU-specific versions of the same definition.

STM32F410.  Add support for STM32Fr10.  STM32F410 is a version of STM32F4 with 32 KB of RAM and 62 or 128 KB of flash.

kinetis:K66 GPIO and pin mux cleanup

Approved-by: Gregory Nutt <gnutt@nuttx.org>