core/cortex-m[0]: Move core functions assembly files to third_party

The code originally comes from libaeabi-cortexm0. It is unclear
which exact git commit the code comes from, but since we have used
it without issue for 5 years, it is reliable, and a refresh is
probably not required at this stage.

BRANCH=none
BUG=chromium:884905
TEST=make buildall -j, which also include basic tests.

Change-Id: I910c1c4e6a46b2f0fe8b7a429f1b6f0f50c2dc21
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1599762
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/third_party/libaeabi-cortexm0/core/cortex-m0/lmul.S b/third_party/libaeabi-cortexm0/core/cortex-m0/lmul.S
new file mode 100644
index 0000000000..ab04fd488f
--- /dev/null
+++ b/third_party/libaeabi-cortexm0/core/cortex-m0/lmul.S
@@ -0,0 +1,65 @@
+/* Runtime ABI for the ARM Cortex-M0
+ * lmul.S: 64 bit multiplication
+ *
+ * Copyright (c) 2013 Jörg Mische <bobbl@gmx.de>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+
+
+	.syntax unified
+	.text
+	.thumb
+	.cpu cortex-m0
+
+
+
+@ long long __aeabi_lmul(long long r1:r0, long long r3:r2)
+@
+@ Multiply r1:r0 and r3:r2 and return the product in r1:r0
+@ Can also be used for unsigned long product
+@
+	.thumb_func
+	.section .text.__aeabi_lmul
+	.global __aeabi_lmul
+__aeabi_lmul:
+
+	push	{r4, lr}
+	muls	r1, r2
+	muls	r3, r0
+	adds	r1, r3
+
+	lsrs	r3, r0, #16
+	lsrs	r4, r2, #16
+	muls	r3, r4
+	adds	r1, r3
+
+	lsrs	r3, r0, #16
+	uxth	r0, r0
+	uxth	r2, r2
+	muls	r3, r2
+	muls	r4, r0
+	muls	r0, r2
+
+	movs	r2, #0
+	adds	r3, r4
+	adcs	r2, r2
+	lsls	r2, #16
+	adds	r1, r2
+
+	lsls	r2, r3, #16
+	lsrs	r3, #16
+	adds	r0, r2
+	adcs	r1, r3
+	pop	{r4, pc}