add circuitpython code

1 files changed, 104 insertions, 0 deletions

diff --git a/circuitpython/py/nlrx86.c b/circuitpython/py/nlrx86.c
new file mode 100644
index 0000000..0cc8b9e
--- /dev/null
+++ b/circuitpython/py/nlrx86.c
@@ -0,0 +1,104 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2013-2017 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 "py/mpstate.h"
+
+#if defined(MICROPY_NLR_X86) && MICROPY_NLR_X86
+
+#undef nlr_push
+
+// For reference, x86 callee save regs are:
+//  ebx, esi, edi, ebp, esp, eip
+
+#if defined(MICROPY_NLR_OS_WINDOWS) && MICROPY_NLR_OS_WINDOWS
+unsigned int nlr_push_tail(nlr_buf_t *nlr) asm ("nlr_push_tail");
+#else
+__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr);
+#endif
+
+#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 8
+// Since gcc 8.0 the naked attribute is supported
+#define USE_NAKED (1)
+#define UNDO_PRELUDE (0)
+#elif defined(__ZEPHYR__) || defined(__ANDROID__)
+// Zephyr and Android use a different calling convention by default
+#define USE_NAKED (0)
+#define UNDO_PRELUDE (0)
+#else
+#define USE_NAKED (0)
+#define UNDO_PRELUDE (1)
+#endif
+
+#if USE_NAKED
+__attribute__((naked))
+#endif
+unsigned int nlr_push(nlr_buf_t *nlr) {
+    (void)nlr;
+
+    __asm volatile (
+        #if UNDO_PRELUDE
+        "pop    %ebp                \n" // undo function's prelude
+        #endif
+        "mov    4(%esp), %edx       \n" // load nlr_buf
+        "mov    (%esp), %eax        \n" // load return %eip
+        "mov    %eax, 8(%edx)       \n" // store %eip into nlr_buf
+        "mov    %ebp, 12(%edx)      \n" // store %ebp into nlr_buf
+        "mov    %esp, 16(%edx)      \n" // store %esp into nlr_buf
+        "mov    %ebx, 20(%edx)      \n" // store %ebx into nlr_buf
+        "mov    %edi, 24(%edx)      \n" // store %edi into nlr_buf
+        "mov    %esi, 28(%edx)      \n" // store %esi into nlr_buf
+        "jmp    nlr_push_tail       \n" // do the rest in C
+        );
+
+    #if !USE_NAKED
+    return 0; // needed to silence compiler warning
+    #endif
+}
+
+NORETURN void nlr_jump(void *val) {
+    MP_NLR_JUMP_HEAD(val, top)
+
+    __asm volatile (
+        "mov    %0, %%edx           \n" // %edx points to nlr_buf
+        "mov    28(%%edx), %%esi    \n" // load saved %esi
+        "mov    24(%%edx), %%edi    \n" // load saved %edi
+        "mov    20(%%edx), %%ebx    \n" // load saved %ebx
+        "mov    16(%%edx), %%esp    \n" // load saved %esp
+        "mov    12(%%edx), %%ebp    \n" // load saved %ebp
+        "mov    8(%%edx), %%eax     \n" // load saved %eip
+        "mov    %%eax, (%%esp)      \n" // store saved %eip to stack
+        "xor    %%eax, %%eax        \n" // clear return register
+        "inc    %%al                \n" // increase to make 1, non-local return
+        "ret                        \n" // return
+        :                           // output operands
+        : "r" (top)                 // input operands
+        :                           // clobbered registers
+        );
+
+    MP_UNREACHABLE
+}
+
+#endif // MICROPY_NLR_X86