[Core] Add support for RISC-V builds and GD32VF103 MCU (#12508)

* Add support for RISC-V builds and GD32VF103 MCU

* Add toolchain selection in chibios.mk based on the mcu selected in
mcu_selection.mk
* Reorder and added comments to chibios.mk to have a streamlined makefile
* Add GD32VF103 mcu to possible targets for QMK.
* Add STM32 compatibility for GD32VF103 MCU, this is hacky but more efficent
  then rewriting every driver.
* Add GigaDevice DFU bootloader as flash target, please note that
  dfu-util of at least version 0.10 is needed.
* Add analog driver compatibility
* Add apa102 bitbang driver compatibility
* Add ws2812 bitbang driver compatibility
* Add eeprom in flash emulation compatibility
* Allow faster re-builds with ccache

* Add SiPeed Longan Nano to platform files

* Add SiPeed Longan Nano Onekeys

* Make quine compatible with other bootloaders

* Support builds with picolibc

* Add risc-v toolchain to arch and debian/ubuntu scripts

8 files changed, 129 insertions, 2 deletions

diff --git a/keyboards/handwired/onekey/keymaps/quine/rules.mk b/keyboards/handwired/onekey/keymaps/quine/rules.mk
deleted file mode 100644
index 4c2b0289a2..0000000000
--- a/keyboards/handwired/onekey/keymaps/quine/rules.mk
+++ /dev/null
@@ -1 +0,0 @@
-BOOTLOADER = atmel-dfu
diff --git a/keyboards/handwired/onekey/readme.md b/keyboards/handwired/onekey/readme.md
index b630b11748..2973b7d873 100644
--- a/keyboards/handwired/onekey/readme.md
+++ b/keyboards/handwired/onekey/readme.md
@@ -3,7 +3,7 @@
 Custom handwired one key keyboard. **See each individual board for pin information.**
 
 * Keyboard Maintainer: QMK Community
-* Hardware Supported: bluepill, Elite-C, Pro Micro, Proton C, Teensy 2.0, Teensy++ 2.0, Teensy LC, Teensy 3.2
+* Hardware Supported: Blackpill F401/F411, Bluepill, Elite-C, Pro Micro, Proton C, Sipeed Longan Nano, STM32F0 Disco, Teensy 2.0, Teensy++ 2.0, Teensy LC, Teensy 3.2
 * Hardware Availability: *n/a*
 
 Make example for this keyboard (after setting up your build environment):
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/chconf.h b/keyboards/handwired/onekey/sipeed_longan_nano/chconf.h
new file mode 100644
index 0000000000..b1eb18de78
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/chconf.h
@@ -0,0 +1,23 @@
+/* Copyright 2021 QMK
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#define CH_CFG_ST_RESOLUTION 16
+
+#define CH_CFG_ST_FREQUENCY 10000
+
+#include_next <chconf.h>
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/config.h b/keyboards/handwired/onekey/sipeed_longan_nano/config.h
new file mode 100644
index 0000000000..1825b936d8
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/config.h
@@ -0,0 +1,37 @@
+/* Copyright 2021 QMK
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "config_common.h"
+
+#define MATRIX_COL_PINS \
+    { B0 }
+#define MATRIX_ROW_PINS \
+    { A7 }
+#define UNUSED_PINS
+
+#define BACKLIGHT_PIN A1           /* Green LED. */
+#define BACKLIGHT_PWM_DRIVER PWMD5 /* GD32 numbering scheme starts from 0, TIMER4 on GD32 boards is TIMER5 on STM32 boards. */
+#define BACKLIGHT_PWM_CHANNEL 2    /* GD32 numbering scheme starts from 0, Channel 1 on GD32 boards is Channel 2 on STM32 boards. */
+
+#define RGB_DI_PIN A2
+#define RGB_CI_PIN B13
+
+#define ADC_PIN A0
+
+#define I2C1_CLOCK_SPEED 1000000 /* GD32VF103 supports fast mode plus. */
+#define I2C1_DUTY_CYCLE FAST_DUTY_CYCLE_2
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/halconf.h b/keyboards/handwired/onekey/sipeed_longan_nano/halconf.h
new file mode 100644
index 0000000000..2579c58747
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/halconf.h
@@ -0,0 +1,23 @@
+/* Copyright 2021 QMK
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#define HAL_USE_PWM TRUE
+#define HAL_USE_ADC TRUE
+#define HAL_USE_I2C TRUE
+
+#include_next <halconf.h>
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/mcuconf.h b/keyboards/handwired/onekey/sipeed_longan_nano/mcuconf.h
new file mode 100644
index 0000000000..eba0dd9eeb
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/mcuconf.h
@@ -0,0 +1,29 @@
+/*
+    ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio
+    ChibiOS - Copyright (C) 2021 Stefan Kerkmann
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+#pragma once
+
+#include_next <mcuconf.h>
+
+#undef GD32_ADC_USE_ADC0
+#define GD32_ADC_USE_ADC0 TRUE
+
+#undef GD32_I2C_USE_I2C0
+#define GD32_I2C_USE_I2C0 TRUE
+
+#undef GD32_PWM_USE_TIM4
+#define GD32_PWM_USE_TIM4 TRUE
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/readme.md b/keyboards/handwired/onekey/sipeed_longan_nano/readme.md
new file mode 100644
index 0000000000..0a3a291576
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/readme.md
@@ -0,0 +1,5 @@
+# Sipeed Longan Nano onekey
+
+Supported Hardware: *GD32VF103CB Sipeed Longan Nano*.
+
+To trigger keypress, short together pins *B0* and *A7*.
\ No newline at end of file
diff --git a/keyboards/handwired/onekey/sipeed_longan_nano/rules.mk b/keyboards/handwired/onekey/sipeed_longan_nano/rules.mk
new file mode 100644
index 0000000000..aef4fee6b2
--- /dev/null
+++ b/keyboards/handwired/onekey/sipeed_longan_nano/rules.mk
@@ -0,0 +1,11 @@
+# MCU name
+MCU   = GD32VF103
+BOARD = SIPEED_LONGAN_NANO
+
+# Bootloader selection
+BOOTLOADER = gd32v-dfu
+
+# Build Options
+#   change yes to no to disable
+#
+KEYBOARD_SHARED_EP = yes