[cli] add cli-radio build (#6769)

Background:

In an early stage of developing a new product, developers may want to
verify the Thread related hardware functionality, for example, send,
receive, etc.  However if the product uses the posix <-> RCP mode,
it's hard to verify it before the posix daemon can run on the
host. cli-ftd and cli-mtd could be an alternative. However, if the
product uses the posix <-> RCP mode, the space of the 802.15.4 radio
chip will be very small. For example, nRF52811 doesn't have enough
space to flash cli-ftd or cli-mtd firmware. So this PR creates a new
firmware ot-cli-radio which has very limited functionality for
verifying the hardware.

Basically, the ot-cli-radio consists of openthread-radio and
libopenthread-cli-radio.a. It supports very few cli commands. The most
important command is diag. Currently, there are: diag, help, reset,
version.

Currently, the diag commands have different implementation on RCP:

- For commands like diag start, the process function
  (Diags::ProcessStart) is first called on host. Then host sends an
  SPI frame to the RCP and Diags::ProcessStart (different
  implementation) is called again on RCP.

- For commands like diag send, Diags::ProcessSend is first called on
  host.  Then host sends an SPI frame to the RCP, directly calling
  send API. And there is no Diags::ProcessSend implemented on RCP.

Let's call the implementation of Diags::Process* currently on host as
native diag commands. When we run ot-cli-radio, we should use the
native diag commands because it won't interact with a posix daemon and
it processes the diag commands through the whole process. So this PR
adds a new option OPENTHREAD_CONFIG_DIAG_NATIVE_CMDS_ON_RCP to control
whether to use the native diag implementation on RCP. When we use a
normal RCP, the option should be disabled. While when use
ot-cli-radio, the option should be enabled.

examples/apps/cli/CMakeLists.txt

@@ -39,3 +39,7 @@ endif()
 if(OT_MTD)
     include(mtd.cmake)
 endif()
+
+if(OT_RCP)
+    include(radio.cmake)
+endif()

examples/apps/cli/Makefile.am

@@ -120,9 +120,40 @@ ot_cli_mtd_SOURCES                                                     = \
     $(SOURCES_COMMON)                                                    \
     $(NULL)
 
+if OPENTHREAD_ENABLE_RADIO_CLI
+bin_PROGRAMS                                                            += \
+    ot-cli-radio                                                           \
+    $(NULL)
+endif
+
+ot_cli_radio_CPPFLAGS                                                    = \
+    $(CPPFLAGS_COMMON)                                                     \
+    $(NULL)
+
+ot_cli_radio_LDADD                                                       = \
+    $(top_builddir)/src/cli/libopenthread-cli-radio.a                      \
+    $(top_builddir)/src/core/libopenthread-radio-cli.a                     \
+    $(LDADD_COMMON)                                                        \
+    $(top_builddir)/src/core/libopenthread-radio-cli.a                     \
+    $(LDADD_COMMON)                                                        \
+    $(NULL)
+
+ot_cli_radio_LDFLAGS                                                     = \
+    $(LDFLAGS_COMMON)                                                      \
+    $(NULL)
+
+ot_cli_radio_LIBTOOLFLAGS                                                = \
+    $(LIBTOOLFLAGS_COMMON)                                                 \
+    $(NULL)
+
+ot_cli_radio_SOURCES                                                     = \
+    $(SOURCES_COMMON)                                                      \
+    $(NULL)
+
 if OPENTHREAD_ENABLE_LINKER_MAP
 ot_cli_ftd_LDFLAGS                                                    += -Wl,-Map=ot-cli-ftd.map
 ot_cli_mtd_LDFLAGS                                                    += -Wl,-Map=ot-cli-mtd.map
+ot_cli_radio_LDFLAGS                                                  += -Wl,-Map=ot-cli-radio.map
 endif
 
 if OPENTHREAD_BUILD_COVERAGE

examples/apps/cli/radio.cmake

@@ -0,0 +1,48 @@
+#
+#  Copyright (c) 2021, The OpenThread Authors.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#  1. Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#  3. Neither the name of the copyright holder nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+
+add_executable(ot-cli-radio
+    cli_uart.cpp
+    main.c
+)
+
+target_include_directories(ot-cli-radio PRIVATE ${COMMON_INCLUDES})
+
+target_link_libraries(ot-cli-radio PRIVATE
+    openthread-cli-radio
+    ${OT_PLATFORM_LIB}
+    openthread-radio-cli
+    ${OT_PLATFORM_LIB}
+    openthread-cli-radio
+    ${OT_MBEDTLS}
+    ot-config
+)
+
+install(TARGETS ot-cli-radio
+    DESTINATION bin
+)