rp2: Add new port to Raspberry Pi RP2 microcontroller.

This commit adds a new port "rp2" which targets the new Raspberry Pi RP2040
microcontroller.

The build system uses pure cmake (with a small Makefile wrapper for
convenience).  The USB driver is TinyUSB, and there is a machine module
with most of the standard classes implemented.  Some examples are provided
in the examples/rp2/ directory.

Work done in collaboration with Graham Sanderson.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 208 insertions, 0 deletions

diff --git a/ports/rp2/main.c b/ports/rp2/main.c
new file mode 100644
index 000000000..3e956ae78
--- /dev/null
+++ b/ports/rp2/main.c
@@ -0,0 +1,208 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020-2021 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+
+#include "py/compile.h"
+#include "py/runtime.h"
+#include "py/gc.h"
+#include "py/mperrno.h"
+#include "py/stackctrl.h"
+#include "lib/mp-readline/readline.h"
+#include "lib/utils/gchelper.h"
+#include "lib/utils/pyexec.h"
+#include "tusb.h"
+#include "uart.h"
+#include "modmachine.h"
+#include "modrp2.h"
+#include "genhdr/mpversion.h"
+
+#include "pico/stdlib.h"
+#include "pico/binary_info.h"
+#include "hardware/rtc.h"
+#include "hardware/structs/rosc.h"
+
+extern uint8_t __StackTop, __StackBottom;
+static char gc_heap[192 * 1024];
+
+// Embed version info in the binary in machine readable form
+bi_decl(bi_program_version_string(MICROPY_GIT_TAG));
+
+// Add a section to the picotool output similar to program features, but for frozen modules
+// (it will aggregate BINARY_INFO_ID_MP_FROZEN binary info)
+bi_decl(bi_program_feature_group_with_flags(BINARY_INFO_TAG_MICROPYTHON,
+    BINARY_INFO_ID_MP_FROZEN, "frozen modules",
+    BI_NAMED_GROUP_SEPARATE_COMMAS | BI_NAMED_GROUP_SORT_ALPHA));
+
+int main(int argc, char **argv) {
+    #if MICROPY_HW_ENABLE_UART_REPL
+    bi_decl(bi_program_feature("UART REPL"))
+    setup_default_uart();
+    mp_uart_init();
+    #endif
+
+    #if MICROPY_HW_ENABLE_USBDEV
+    bi_decl(bi_program_feature("USB REPL"))
+    tusb_init();
+    #endif
+
+    #if MICROPY_PY_THREAD
+    bi_decl(bi_program_feature("thread support"))
+    mp_thread_init();
+    #endif
+
+    // Start and initialise the RTC
+    datetime_t t = {
+        .year = 2021,
+        .month = 1,
+        .day = 1,
+        .dotw = 5, // 0 is Sunday, so 5 is Friday
+        .hour = 0,
+        .min = 0,
+        .sec = 0,
+    };
+    rtc_init();
+    rtc_set_datetime(&t);
+
+    // Initialise stack extents and GC heap.
+    mp_stack_set_top(&__StackTop);
+    mp_stack_set_limit(&__StackTop - &__StackBottom - 256);
+    gc_init(&gc_heap[0], &gc_heap[MP_ARRAY_SIZE(gc_heap)]);
+
+    for (;;) {
+
+        // Initialise MicroPython runtime.
+        mp_init();
+        mp_obj_list_init(MP_OBJ_TO_PTR(mp_sys_path), 0);
+        mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR_));
+        mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_lib));
+        mp_obj_list_init(MP_OBJ_TO_PTR(mp_sys_argv), 0);
+
+        // Initialise sub-systems.
+        readline_init0();
+        machine_pin_init();
+        rp2_pio_init();
+
+        // Execute _boot.py to set up the filesystem.
+        pyexec_frozen_module("_boot.py");
+
+        // Execute user scripts.
+        pyexec_file_if_exists("boot.py");
+        if (pyexec_mode_kind == PYEXEC_MODE_FRIENDLY_REPL) {
+            pyexec_file_if_exists("main.py");
+        }
+
+        for (;;) {
+            if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
+                if (pyexec_raw_repl() != 0) {
+                    break;
+                }
+            } else {
+                if (pyexec_friendly_repl() != 0) {
+                    break;
+                }
+            }
+        }
+
+        mp_printf(MP_PYTHON_PRINTER, "MPY: soft reboot\n");
+        rp2_pio_deinit();
+        machine_pin_deinit();
+        gc_sweep_all();
+        mp_deinit();
+    }
+
+    return 0;
+}
+
+void gc_collect(void) {
+    gc_collect_start();
+    gc_helper_collect_regs_and_stack();
+    #if MICROPY_PY_THREAD
+    mp_thread_gc_others();
+    #endif
+    gc_collect_end();
+}
+
+void nlr_jump_fail(void *val) {
+    printf("FATAL: uncaught exception %p\n", val);
+    mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(val));
+    for (;;) {
+        __breakpoint();
+    }
+}
+
+#ifndef NDEBUG
+void MP_WEAK __assert_func(const char *file, int line, const char *func, const char *expr) {
+    printf("Assertion '%s' failed, at file %s:%d\n", expr, file, line);
+    panic("Assertion failed");
+}
+#endif
+
+uint32_t rosc_random_u32(void) {
+    uint32_t value = 0;
+    for (size_t i = 0; i < 32; ++i) {
+        value = value << 1 | rosc_hw->randombit;
+    }
+    return value;
+}
+
+const char rp2_help_text[] =
+    "Welcome to MicroPython!\n"
+    "\n"
+    "For online help please visit https://micropython.org/help/.\n"
+    "\n"
+    "For access to the hardware use the 'machine' module.  RP2 specific commands\n"
+    "are in the 'rp2' module.\n"
+    "\n"
+    "Quick overview of some objects:\n"
+    "  machine.Pin(pin) -- get a pin, eg machine.Pin(0)\n"
+    "  machine.Pin(pin, m, [p]) -- get a pin and configure it for IO mode m, pull mode p\n"
+    "    methods: init(..), value([v]), high(), low(), irq(handler)\n"
+    "  machine.ADC(pin) -- make an analog object from a pin\n"
+    "    methods: read_u16()\n"
+    "  machine.PWM(pin) -- make a PWM object from a pin\n"
+    "    methods: deinit(), freq([f]), duty_u16([d]), duty_ns([d])\n"
+    "  machine.I2C(id) -- create an I2C object (id=0,1)\n"
+    "    methods: readfrom(addr, buf, stop=True), writeto(addr, buf, stop=True)\n"
+    "             readfrom_mem(addr, memaddr, arg), writeto_mem(addr, memaddr, arg)\n"
+    "  machine.SPI(id, baudrate=1000000) -- create an SPI object (id=0,1)\n"
+    "    methods: read(nbytes, write=0x00), write(buf), write_readinto(wr_buf, rd_buf)\n"
+    "  machine.Timer(freq, callback) -- create a software timer object\n"
+    "    eg: machine.Timer(freq=1, callback=lambda t:print(t))\n"
+    "\n"
+    "Pins are numbered 0-29, and 26-29 have ADC capabilities\n"
+    "Pin IO modes are: Pin.IN, Pin.OUT, Pin.ALT\n"
+    "Pin pull modes are: Pin.PULL_UP, Pin.PULL_DOWN\n"
+    "\n"
+    "Useful control commands:\n"
+    "  CTRL-C -- interrupt a running program\n"
+    "  CTRL-D -- on a blank line, do a soft reset of the board\n"
+    "  CTRL-E -- on a blank line, enter paste mode\n"
+    "\n"
+    "For further help on a specific object, type help(obj)\n"
+    "For a list of available modules, type help('modules')\n"
+;
+