[chibios] Add support for a full ChibiOS arch (#1699)

[chibios] Add support for a full ChibiOS arch

This is replacing the previous mix chibios/libopencm3:
- all drivers are ported to the new arch
- it was hard to go forward and take advantages of the RTOS, now it is much easier
- switch to v3 of ChibiOS
- for now, it is functionaly the same than before
- the previous variable length array mechanism used internaly by the
  sdlog is replaced by a more efficient library called TLSF (allow
  constant time malloc/free)

sw/ext/tlsf/readme.txt

@@ -0,0 +1 @@
+see http://tlsf.baisoku.org

sw/ext/tlsf/tlsf.h

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+#pragma once
+
+/*
+** Two Level Segregated Fit memory allocator, version 3.0.
+** Written by Matthew Conte, and placed in the Public Domain.
+**	http://tlsf.baisoku.org
+**
+** Based on the original documentation by Miguel Masmano:
+**	http://rtportal.upv.es/rtmalloc/allocators/tlsf/index.shtml
+**
+** Please see the accompanying Readme.txt for implementation
+** notes and caveats.
+**
+** This implementation was written to the specification
+** of the document, therefore no GPL restrictions apply.
+*/
+
+#include <stddef.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+/* tlsf_t: a TLSF structure. Can contain 1 to N pools. */
+/* pool_t: a block of memory that TLSF can manage. */
+typedef void* tlsf_t;
+typedef void* pool_t;
+typedef void (*error_cb_t) (const char *msg);
+
+/* Create/destroy a memory pool. */
+tlsf_t tlsf_create(void* mem, error_cb_t error_cb);
+tlsf_t tlsf_create_with_pool(void* mem, size_t bytes, error_cb_t error_cb);
+void tlsf_destroy(tlsf_t tlsf);
+pool_t tlsf_get_pool(tlsf_t tlsf);
+
+/* Add/remove memory pools. */
+pool_t tlsf_add_pool(tlsf_t tlsf, void* mem, size_t bytes);
+void tlsf_remove_pool(tlsf_t tlsf, pool_t pool);
+
+/* malloc/memalign/realloc/free replacements. */
+void* tlsf_malloc(tlsf_t tlsf, size_t bytes);
+void* tlsf_memalign(tlsf_t tlsf, size_t align, size_t bytes);
+void* tlsf_realloc(tlsf_t tlsf, void* ptr, size_t size);
+void tlsf_free(tlsf_t tlsf, void* ptr);
+
+/* Returns internal block size, not original request size */
+size_t tlsf_block_size(void* ptr);
+
+/* Overheads/limits of internal structures. */
+size_t tlsf_size(void);
+size_t tlsf_align_size(void);
+size_t tlsf_block_size_min(void);
+size_t tlsf_block_size_max(void);
+size_t tlsf_pool_overhead(void);
+size_t tlsf_alloc_overhead(void);
+
+/* Debugging. */
+typedef void (*tlsf_walker)(void* ptr, size_t size, int used, void* user);
+void tlsf_walk_pool(pool_t pool, tlsf_walker walker, void* user);
+/* Returns nonzero if any internal consistency check fails. */
+int tlsf_check(tlsf_t tlsf);
+int tlsf_check_pool(pool_t pool);
+
+#if defined(__cplusplus)
+};
+#endif
+
+