0001-Rewrite-__eabi_read_tp-in-c.patch

From d49cc3a9c2bc3d7bbc8de05b934bd6824285d330 Mon Sep 17 00:00:00 2001
From: Steven van der Schoot <stevenvdschoot@gmail.com>
Date: Wed, 28 Dec 2022 15:19:54 +0100
Subject: [PATCH] Rewrite __eabi_read_tp in c

---
 .../libc/picolib/machine/arm/CMakeLists.txt   |  2 +-
 newlib/libc/picolib/machine/arm/meson.build   |  2 +-
 newlib/libc/picolib/machine/arm/read_tp.S     | 69 -------------------
 newlib/libc/picolib/machine/arm/read_tp.c     | 18 +++++
 4 files changed, 20 insertions(+), 71 deletions(-)
 delete mode 100644 newlib/libc/picolib/machine/arm/read_tp.S
 create mode 100644 newlib/libc/picolib/machine/arm/read_tp.c

diff --git a/newlib/libc/picolib/machine/arm/CMakeLists.txt b/newlib/libc/picolib/machine/arm/CMakeLists.txt
index 4e40da4e3..8d66f7013 100644
--- a/newlib/libc/picolib/machine/arm/CMakeLists.txt
+++ b/newlib/libc/picolib/machine/arm/CMakeLists.txt
@@ -38,6 +38,6 @@ picolibc_sources(interrupt.c)
 if(${_HAVE_PICOLIBC_TLS_API})
   picolibc_sources(
     tls.c
-    read_tp.S
+    read_tp.c
     )
 endif()
diff --git a/newlib/libc/picolib/machine/arm/meson.build b/newlib/libc/picolib/machine/arm/meson.build
index 766ea5416..2c3b2ec6c 100644
--- a/newlib/libc/picolib/machine/arm/meson.build
+++ b/newlib/libc/picolib/machine/arm/meson.build
@@ -35,5 +35,5 @@
 
 src_picolib += files('interrupt.c')
 if thread_local_storage
-  src_picolib += files('tls.c', 'read_tp.S')
+  src_picolib += files('tls.c', 'read_tp.c')
 endif
diff --git a/newlib/libc/picolib/machine/arm/read_tp.S b/newlib/libc/picolib/machine/arm/read_tp.S
deleted file mode 100644
index 78258db12..000000000
--- a/newlib/libc/picolib/machine/arm/read_tp.S
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * SPDX-License-Identifier: BSD-3-Clause
- *
- * Copyright © 2020 Keith Packard
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above
- *    copyright notice, this list of conditions and the following
- *    disclaimer in the documentation and/or other materials provided
- *    with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its
- *    contributors may be used to endorse or promote products derived
- *    from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-#include "arm_tls.h"
-/*
- * This cannot be a C ABI function as the compiler assumes that it
- * does not modify anything other than r0 and lr.
- */
-	.syntax unified
-	.text
-	.align 4
-	.p2align 4,,15
-	.global __aeabi_read_tp
-	.type __aeabi_read_tp,%function
-#ifdef __thumb__
-	.thumb
-#endif
-
-__aeabi_read_tp:
-	.cfi_sections .debug_frame
-	.cfi_startproc
-#ifdef ARM_TLS_CP15
-	mrc 15, 0, r0, c13, c0, 3
-#else
-	/* Load the address of __tls */
-	ldr r0,1f
-	/* Dereference to get the value of __tls */
-	ldr r0,[r0]
-#endif
-	/* All done, return to caller */
-	bx lr
-	.cfi_endproc
-	
-	/* Holds the address of __tls */
-	.align 2
-#ifndef ARM_TLS_CP15
-1: .word __tls
-#endif
diff --git a/newlib/libc/picolib/machine/arm/read_tp.c b/newlib/libc/picolib/machine/arm/read_tp.c
new file mode 100644
index 000000000..c6f68925a
--- /dev/null
+++ b/newlib/libc/picolib/machine/arm/read_tp.c
@@ -0,0 +1,18 @@
+#include "arm_tls.h"
+
+#ifndef ARM_TLS_CP15
+extern void *__tls;
+#endif
+
+void *
+__aeabi_read_tp(void)
+{
+#ifdef ARM_TLS_CP15
+    // mrc 15, 0, r0, c13, c0, 3
+    void *result;
+    __asm__("mcr 15, 0, %0, c13, c0, 3" : "=r"(result) :);
+    return result;
+#else
+    return __tls;
+#endif
+}
-- 
2.38.1