variants: add nano rp2040 connect

.gitignore

@@ -8,3 +8,4 @@ cxxflags.txt
 includes.txt
 syms-dynamic.ld
 syms-static.ld
+tls-syms.S

boards.txt

@@ -757,4 +757,71 @@ unoq.bootloader.tool.default=remoteocd
 unoq.bootloader.file=zephyr-{build.variant}.elf
 unoq.bootloader.target=stm32u585zitxq
 
-##########################################################################################
+##############################################################################################################
+
+nano_connect.name=Arduino Nano RP2040 Connect
+nano_connect.build.core=arduino
+nano_connect.build.crossprefix=arm-zephyr-eabi-
+nano_connect.build.compiler_path={runtime.tools.arm-zephyr-eabi-0.16.8.path}/bin/
+
+nano_connect.menu.debug.false=Standard
+nano_connect.menu.debug.true=Debug
+nano_connect.menu.debug.true.build.zsk_args.debug=-debug
+
+nano_connect.menu.link_mode.dynamic=Dynamic
+nano_connect.menu.link_mode.static=Static
+nano_connect.menu.link_mode.static.build.link_mode=static
+nano_connect.menu.link_mode.static.upload.extension=bin-zsk.bin
+
+nano_connect.build.zephyr_target=arduino_nano_connect
+nano_connect.build.zephyr_args=
+nano_connect.build.zephyr_hals=hal_rpi_pico
+nano_connect.build.artifact=zephyr_main
+nano_connect.build.variant=arduino_nano_connect_rp2040
+nano_connect.build.mcu=cortex-m0plus
+nano_connect.build.fpu=
+nano_connect.build.architecture=cortex-m0plus
+nano_connect.compiler.zephyr.arch.define=
+
+nano_connect.build.float-abi=-mfloat-abi=soft
+nano_connect.build.extra_flags=
+nano_connect.build.postbuild.cmd="{tools.imgtool.path}/{tools.imgtool.cmd}" exit
+nano_connect.recipe.hooks.objcopy.postobjcopy.3.pattern="{runtime.tools.bin2uf2.path}/bin2uf2" {upload.address} {upload.familyid} "{build.path}/{build.project_name}.{upload.extension}" "{build.path}/{build.project_name}.uf2"
+nano_connect.build.board=NANO_RP2040_CONNECT
+nano_connect.compiler.zephyr=
+nano_connect.vid.0=0x2341
+nano_connect.pid.0=0x005E
+nano_connect.upload_port.0.vid=0x2341
+nano_connect.upload_port.0.pid=0x005E
+
+nano_connect.upload.tool=picotool
+nano_connect.upload.tool.default=picotool
+nano_connect.upload.protocol=
+nano_connect.upload.transport=
+nano_connect.upload.vid=0x2341
+nano_connect.upload.pid=0x005E
+nano_connect.upload.interface=0
+nano_connect.upload.use_1200bps_touch=true
+nano_connect.upload.wait_for_upload_port=false
+nano_connect.upload.native_usb=true
+nano_connect.upload.maximum_size=16777216
+nano_connect.upload.maximum_data_size=270336
+
+nano_connect.upload.address=0x100E0000
+nano_connect.upload.familyid=0xe48bff56
+
+nano_connect.bootloader.tool=picotool
+nano_connect.bootloader.tool.default=picotool
+nano_connect.bootloader.vid=0x2341
+nano_connect.bootloader.pid=0x005E
+nano_connect.bootloader.interface=0
+nano_connect.bootloader.file=zephyr-{build.variant}
+
+nano_connect.debug.tool=gdb
+nano_connect.debug.server.openocd.scripts.0=interface/{programmer.protocol}.cfg
+nano_connect.debug.server.openocd.scripts.1={programmer.transport_script}
+nano_connect.debug.server.openocd.scripts.2=target/rp2040-core0.cfg
+nano_connect.debug.cortex-debug.custom.request=attach
+nano_connect.debug.svd_file={runtime.platform.path}/svd/rp2040.svd
+
+##############################################################################################################

cores/arduino/llext_wrappers.c

@@ -62,6 +62,25 @@
 		__real_##name(a);                                                                          \
 	}
 
+#ifdef CONFIG_ARM
+/* ARM EABI thread pointer access */
+W0(size_t, __aeabi_read_tp)
+
+/*
+ * Thumb1 switch-dispatch helpers.
+ *
+ * These use a non-standard calling convention: BL sets LR to the jump table
+ * base (not a return address). With -mlong-calls the compiler lowers each
+ * void-void wrapper to a tail call (ldr r3, =addr; bx r3), leaving LR
+ * unchanged so the real function sees the original table pointer.
+ */
+V0(__gnu_thumb1_case_uqi)
+V0(__gnu_thumb1_case_sqi)
+V0(__gnu_thumb1_case_uhi)
+V0(__gnu_thumb1_case_shi)
+V0(__gnu_thumb1_case_si)
+#endif
+
 /* string.h */
 W3(void *, memcpy, void *, const void *, size_t)
 W3(void *, memmove, void *, const void *, size_t)

extra/build.sh

@@ -91,7 +91,7 @@ line_continuation='\\$' # match lines ending with '\'
 c_comment='\s*\/\*.*?\*\/' # match C-style comments and any preceding space
 perl -i -pe "s/${c_comment}//gs unless /${line_preproc_ok}/ || (/${line_comment_only}/ && !/${line_continuation}/)" $(find ${VARIANT_DIR}/llext-edk/include/ -type f)
 
-for ext in elf bin hex; do
+for ext in elf bin hex uf2; do
     rm -f firmwares/zephyr-$variant.$ext
     if [ -f ${BUILD_DIR}/zephyr/zephyr.$ext ]; then
         cp ${BUILD_DIR}/zephyr/zephyr.$ext firmwares/zephyr-$variant.$ext
@@ -102,6 +102,7 @@ cp ${BUILD_DIR}/zephyr/.config firmwares/zephyr-$variant.config
 
 # Generate the provides.ld file for linked builds
 echo "Generating exported symbol scripts"
+extra/gen_provides.py "${BUILD_DIR}/zephyr/zephyr.elf" -T > ${VARIANT_DIR}/tls-syms.S
 extra/gen_provides.py "${BUILD_DIR}/zephyr/zephyr.elf" -L > ${VARIANT_DIR}/syms-dynamic.ld
 extra/gen_provides.py "${BUILD_DIR}/zephyr/zephyr.elf" -LF \
 	"+kheap_llext_heap" \

extra/gen_provides.py

@@ -122,17 +122,29 @@ def main():
     argparser.add_argument('-F', '--funcs',
             action='store_true',
             help='Extract all public functions')
+    argparser.add_argument('-T', '--tls-defs',
+            action='store_true',
+            help='Extract TLS symbol offsets to a .S file')
     argparser.add_argument('file',
             help='ELF file to parse')
     argparser.add_argument('syms', nargs='*',
             help='Symbols to export')
 
     args = argparser.parse_intermixed_args()
 
+    wants_provides = bool(args.syms or args.funcs or args.llext)
+    if wants_provides and args.tls_defs:
+        sys.stderr.write("Cannot generate TLS defs when also generating PROVIDEs.\n")
+        sys.exit(1)
+    elif not wants_provides and not args.tls_defs:
+        sys.stderr.write("Nothing specified for export.\n")
+        sys.exit(1)
+
     exact_syms = set()
     regex_syms = set()
     deref_syms = set()
     sized_syms = set()
+    tls_syms = set() # tuple of (name, value, size)
     rename_map = {}
     for sym in args.syms:
         sym_class = None
@@ -184,6 +196,11 @@ def main():
         fail = False
 
         for name, sym in all_syms.items():
+            if sym['st_info']['type'] == 'STT_TLS':
+                # Collect TLS symbol information, ignore for PROVIDEs
+                tls_syms.add((name, sym['st_value'], sym['st_size']))
+                continue
+
             value = None
             comment = []
             if name in exact_syms or any(re.match(r, name) for r in regex_syms):
@@ -220,10 +237,6 @@ def main():
             if name in sized_syms:
                 out_syms[name + "_size"] = (sym['st_size'], [f"size of {name}"])
 
-        if not out_syms:
-            sys.stderr.write("No symbols found matching the criteria.\n")
-            fail = True
-
         if fail:
             sys.exit(1)
 
@@ -235,16 +248,47 @@ def main():
  * SHA256: {elf_sha}
  */
 """)
-        sym_comment = nul_comment = ""
-        for name, (value, comments) in sorted(out_syms.items(), key=lambda x: x[0]):
-            if args.verbose:
-                comment = ', '.join(sorted(comments))
-                sym_comment = f"/* {comment} */"
-                nul_comment = f" ({comment})"
-            if value:
-                print(f"PROVIDE({name} = {value:#010x});{sym_comment}")
+
+        if wants_provides:
+            if not out_syms:
+                print("/* No symbols found matching the criteria */")
+                sys.stderr.write("warning: no symbols found matching the criteria.\n")
             else:
-                print(f"/* NULL {name}{nul_comment} */")
+                sym_comment = nul_comment = ""
+                for name, (value, comments) in sorted(out_syms.items(), key=lambda x: x[0]):
+                    if args.verbose:
+                        comment = ', '.join(sorted(comments))
+                        sym_comment = f"/* {comment} */"
+                        nul_comment = f" ({comment})"
+                    if value:
+                        print(f"PROVIDE({name} = {value:#010x});{sym_comment}")
+                    else:
+                        print(f"/* NULL {name}{nul_comment} */")
+
+        if args.tls_defs:
+            # ARM and AArch64 use '@' as a line-comment character in GAS, so the
+            # assembler requires '%' as the type prefix there.  All other targets use '@'.
+            prefix = '%' if elf['e_machine'] in ('EM_ARM', 'EM_AARCH64') else '@'
+
+            # The TLS Variant 1 layout (used by ARM/AArch64) places a Thread
+            # Control Block (TCB) before the TLS data.  The thread pointer
+            # returned by __aeabi_read_tp() points to the TCB, so the actual
+            # runtime address of a TLS variable must be offset by that size.
+            #
+            # TCB is 2 pointers: 8 bytes on 32-bit, 16 bytes on 64-bit.
+            # See zephyr/arch/arm/core/tls.c: arch_tls_stack_setup().
+            tcb_size = (elf.elfclass // 8) * 2
+            print(f"/* Offsets include {tcb_size} bytes for TCB data */")
+
+            # Sort by offset first, then size
+            for name, offset, size in sorted(tls_syms, key=lambda x: (x[1], x[2])):
+                offset += tcb_size
+                print(
+                    f"\n/* TLS offset {offset:#x}: {name} ({size} bytes) */\n"
+                    f".global {name}\n"
+                    f".type {name}, {prefix}tls_object\n"
+                    f".set {name}, {offset}"
+                )
 
 #-------------------------------------------------------------------------------
 if __name__ == '__main__':

libraries/SPI/SPI.cpp

@@ -115,7 +115,9 @@ void arduino::ZephyrSPI::detachInterrupt() {
 }
 
 void arduino::ZephyrSPI::begin() {
-	spi_dev->ops.init(spi_dev);
+	if (!device_is_ready(spi_dev)) {
+		spi_dev->ops.init(spi_dev);
+	}
 }
 
 void arduino::ZephyrSPI::end() {

loader/fixups.c

@@ -53,6 +53,53 @@ SYS_INIT(disable_bootloader_mpu, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAU
 SYS_INIT(disable_mpu_rasr_xn, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
 #endif
 
+#if defined(CONFIG_BOARD_ARDUINO_NANO_RP2040_CONNECT)
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
+#include <pico/bootrom.h>
+
+/*
+ * Double-tap reset detection: if the board is reset twice within 500ms,
+ * enter USB bootloader (BOOTSEL) mode. This mirrors the original
+ * ArduinoCore-mbed NANO_RP2040_CONNECT behavior.
+ *
+ * A magic token is stored in uninitialized RAM (.noinit), which survives
+ * a warm reset but is lost on power cycle. On boot:
+ *   - If the token is present: a second reset happened quickly, so we
+ *     clear the token and enter USB boot mode (never returns).
+ *   - If not: write the token, wait 500ms, then clear it and boot normally.
+ */
+static const uint32_t magic_token[] = {
+	0xf01681de,
+	0xbd729b29,
+	0xd359be7a,
+};
+
+static uint32_t magic_location[3] __attribute__((section(".noinit.double_tap")));
+
+#define NANO_RP2040_LED_PIN 6
+
+int double_tap_check(void) {
+	if (magic_location[0] == magic_token[0] && magic_location[1] == magic_token[1] &&
+		magic_location[2] == magic_token[2]) {
+		magic_location[0] = 0;
+		reset_usb_boot(1 << NANO_RP2040_LED_PIN, 0);
+		/* never returns */
+	}
+
+	for (int i = 0; i < 3; i++) {
+		magic_location[i] = magic_token[i];
+	}
+
+	k_busy_wait(500000);
+
+	magic_location[0] = 0;
+	return 0;
+}
+
+SYS_INIT(double_tap_check, POST_KERNEL, 0);
+#endif
+
 #if defined(CONFIG_INPUT)
 #include <zephyr/kernel.h>
 #include <zephyr/device.h>

loader/llext_exports.c

@@ -297,6 +297,20 @@ EXPORT_SYMBOL(ring_buf_area_finish);
 #endif
 
 EXPORT_SYMBOL(sys_clock_cycle_get_32);
+
+#if defined(CONFIG_ARM)
+extern uint32_t __aeabi_read_tp(void);
+EXPORT_LIBC_SYM(__aeabi_read_tp);
+extern void __gnu_thumb1_case_uqi(void);
+EXPORT_LIBC_SYM(__gnu_thumb1_case_uqi);
+extern void __gnu_thumb1_case_sqi(void);
+EXPORT_LIBC_SYM(__gnu_thumb1_case_sqi);
+extern void __gnu_thumb1_case_uhi(void);
+EXPORT_LIBC_SYM(__gnu_thumb1_case_uhi);
+extern void __gnu_thumb1_case_shi(void);
+EXPORT_LIBC_SYM(__gnu_thumb1_case_shi);
+extern void __gnu_thumb1_case_si(void);
+EXPORT_LIBC_SYM(__gnu_thumb1_case_si);
 FORCE_EXPORT_SYM(__aeabi_dcmpun);
 FORCE_EXPORT_SYM(__aeabi_dcmple);
 FORCE_EXPORT_SYM(__aeabi_d2lz);
@@ -326,6 +340,8 @@ FORCE_EXPORT_SYM(__aeabi_idivmod);
 FORCE_EXPORT_SYM(__aeabi_ldivmod);
 FORCE_EXPORT_SYM(__aeabi_ul2f);
 FORCE_EXPORT_SYM(__aeabi_dcmpge);
+FORCE_EXPORT_SYM(__aeabi_lmul);
+#endif
 
 #if defined (CONFIG_CPP)
 FORCE_EXPORT_SYM(__cxa_pure_virtual);

platform.txt

@@ -249,7 +249,15 @@ tools.picotool.path={runtime.tools.rp2040tools.path}
 tools.picotool.cmd=rp2040load
 tools.picotool.upload.params.verbose=-v
 tools.picotool.upload.params.quiet=
-tools.picotool.upload.pattern="{path}/{cmd}" {upload.verbose} -D "{build.path}/{build.project_name}.elf"
+tools.picotool.upload.pattern="{path}/{cmd}" {upload.verbose} -D "{build.path}/{build.project_name}"
+
+tools.picotool.erase.params.verbose=
+tools.picotool.erase.params.quiet=
+tools.picotool.erase.pattern=
+
+tools.picotool.bootloader.params.verbose=-v
+tools.picotool.bootloader.params.quiet=
+tools.picotool.bootloader.pattern="{path}/{cmd}" {upload.verbose} -D "{runtime.platform.path}/firmwares/{bootloader.file}"
 
 #
 # IMGTOOL

variants/arduino_nano_connect_rp2040/arduino_nano_connect_rp2040.conf

@@ -0,0 +1,34 @@
+# Copyright (c) Arduino s.r.l. and/or its affiliated companies
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_USB_DEVICE_STACK=y
+CONFIG_USB_DEVICE_PRODUCT="Arduino Nano RP2040 Connect"
+CONFIG_USB_DEVICE_MANUFACTURER="Arduino"
+CONFIG_USB_DEVICE_VID=0x2341
+CONFIG_USB_DEVICE_PID=0x005E
+
+CONFIG_SERIAL=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_UART_LINE_CTRL=y
+
+CONFIG_USB_CDC_ACM=y
+CONFIG_USB_CDC_ACM_RINGBUF_SIZE=1024
+CONFIG_UART_LINE_CTRL=y
+CONFIG_CDC_ACM_DTE_RATE_CALLBACK_SUPPORT=y
+
+CONFIG_LLEXT_STORAGE_WRITABLE=n
+
+CONFIG_HEAP_MEM_POOL_SIZE=16384
+CONFIG_MAIN_STACK_SIZE=32768
+CONFIG_LLEXT_HEAP_SIZE=64
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=-1
+
+CONFIG_LOG_BACKEND_UART=y
+CONFIG_LOG_BACKEND_UART_AUTOSTART=n
+CONFIG_LOG_DEFAULT_LEVEL=2
+
+CONFIG_ADC=y
+CONFIG_DAC=n
+CONFIG_PWM=y
+