Add Bluepill (stm32f103) handwired keyboard (#4126)

* Main folder

Main folder with some changes like the base layout and matrix for uploading in a future to the qmk repositorie

* First Commit

Firsts non previously commited changes:
-Changed to keyboards/handwired
-Basic credit to Xydane
-70% Layout

* Modified file structure for several keyboards

As I don't want to create several folders and overcrowd the main folders I made a few modifications to being able of configure several keyboards as revisions of the main keyboard.
Added a second variant.
Compiling tests went right but I haven't tried it on the controller.

* Starting leds

* Started dual color leds PWM functions and configs

I started to create the PWM functions and configs based on internet examples, it doesn't compile yet

* Backtraced a bit to establish and try debug before continuing the pwm

Just this, algo some doc as a new pinout image, space cadet modification to try if it works and little more

* Deleted unuseful stuff

After trying the reestructure to being compatible with several keyboards and that it worked I deleted the other keyboard.
Added space cadet shift to ISO.
Finally I couldn't debug everything and I'm getting quite frustrated to continue much more than just adding pwm leds

* Changed again Iso fix for Space Cadet

* Renamed keyboard, future pull

I just renamed the keyboard and made some simplifying changes in order to make a pull request sometime soon.

I'm too frustrated, tired and knowledge limited to achive using the PWM for leds, I didn't even get to use the debug mode...

I intend to end basic led color change using layers (if I can), document everything properly and make a pull request so other users can continue/use this project.

* Writed Readme.md file

I also corrected a previous compilation problem and ordered a bit the keymaps

* Corrected readme

* Try to add layer activated light

* Revert "Try to add layer activated light"

This reverts commit 205af820d845dab08988f329b9f062f558060220.

* Progress to fork

Coming back to work, upcoming pull

* Linked image

Corrected readme

* Some cleanning

Added images to readme, som cleaning, burning after commit.

* Almost finished (working)

Finally

* Finished bluepill firmware

Just finished and tried layer dependant led colors. Going for merge

* Deleted innecesary stuff and trailing spaces

Just as commit title said.

* Coding conventions

Just modified some files to respect coding conventions

* Deleted XXXXXX define

Checking some other PR seen this improvement

* Changes suggested on PR

Firs doing the easy changes

* More changes for the PR

-I also deleted one unused function for led toggling on matrix.c (Now it uses layer dependent baklight, algo on of on start)
-Deleted commented function on keymaps.

Right now only needs testing and all pragma replaces.

* Almost every pragma change on PR

That's almost finished, only waiting for reply due to compiling errors

* Revert "Almost every pragma change on PR"

This reverts commit 07f23aa862b370cdf0ae37d6f2130c9e9856f491.

* Revert last commit

I moddified by mistake a file from another keyboard

* Solved last pragma

Compiles fine.
Now I only need to test it, I say you if it works to include it in the main repository.

keyboards/handwired/bluepill/ld/STM32F103x8_stm32duino_bootloader.ld

@@ -0,0 +1,88 @@
+/*
+    ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio
+
+    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.
+*/
+
+/*
+ * ST32F103xB memory setup for use with the maplemini bootloader.
+ * You will have to
+ * 	#define CORTEX_VTOR_INIT 0x5000
+ * in your projects chconf.h
+ */
+MEMORY
+{
+    flash0  : org = 0x08002000, len = 128k - 0x2000
+    flash1  : org = 0x00000000, len = 0
+    flash2  : org = 0x00000000, len = 0
+    flash3  : org = 0x00000000, len = 0
+    flash4  : org = 0x00000000, len = 0
+    flash5  : org = 0x00000000, len = 0
+    flash6  : org = 0x00000000, len = 0
+    flash7  : org = 0x00000000, len = 0
+    ram0    : org = 0x20000000, len = 20k
+    ram1    : org = 0x00000000, len = 0
+    ram2    : org = 0x00000000, len = 0
+    ram3    : org = 0x00000000, len = 0
+    ram4    : org = 0x00000000, len = 0
+    ram5    : org = 0x00000000, len = 0
+    ram6    : org = 0x00000000, len = 0
+    ram7    : org = 0x00000000, len = 0
+}
+
+/* For each data/text section two region are defined, a virtual region
+   and a load region (_LMA suffix).*/
+
+/* Flash region to be used for exception vectors.*/
+REGION_ALIAS("VECTORS_FLASH", flash0);
+REGION_ALIAS("VECTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for constructors and destructors.*/
+REGION_ALIAS("XTORS_FLASH", flash0);
+REGION_ALIAS("XTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for code text.*/
+REGION_ALIAS("TEXT_FLASH", flash0);
+REGION_ALIAS("TEXT_FLASH_LMA", flash0);
+
+/* Flash region to be used for read only data.*/
+REGION_ALIAS("RODATA_FLASH", flash0);
+REGION_ALIAS("RODATA_FLASH_LMA", flash0);
+
+/* Flash region to be used for various.*/
+REGION_ALIAS("VARIOUS_FLASH", flash0);
+REGION_ALIAS("VARIOUS_FLASH_LMA", flash0);
+
+/* Flash region to be used for RAM(n) initialization data.*/
+REGION_ALIAS("RAM_INIT_FLASH_LMA", flash0);
+
+/* RAM region to be used for Main stack. This stack accommodates the processing
+   of all exceptions and interrupts.*/
+REGION_ALIAS("MAIN_STACK_RAM", ram0);
+
+/* RAM region to be used for the process stack. This is the stack used by
+   the main() function.*/
+REGION_ALIAS("PROCESS_STACK_RAM", ram0);
+
+/* RAM region to be used for data segment.*/
+REGION_ALIAS("DATA_RAM", ram0);
+REGION_ALIAS("DATA_RAM_LMA", flash0);
+
+/* RAM region to be used for BSS segment.*/
+REGION_ALIAS("BSS_RAM", ram0);
+
+/* RAM region to be used for the default heap.*/
+REGION_ALIAS("HEAP_RAM", ram0);
+
+/* Generic rules inclusion.*/
+INCLUDE rules.ld