From 991ae1e39553172a7dd6cd8c634aebfce892e261 Mon Sep 17 00:00:00 2001
From: Thomas Martitz <kugel@rockbox.org>
Date: Wed, 4 Jan 2012 18:07:21 +0100
Subject: Create fimrware/asm directory for assembly optimized stuff.

This dir is suitable for stuff that doesn't fit the target tree, e.g. because
it also builds on hosted or otherwise. It also has a generic subfolder for
fallback C implementations so that not all archs need to provide asm files.

SOURCES should only contain "foo.c" where foo.c includes the specific
<arch>/foo.c files from the subdirs using the preprocessor. This way automatic
selection of asm versions or generic C verion is possible.

For the start, the thread support files are moved, since ASM threads can
be used on hosted platforms as well. Since core_sleep() remains platform
specific it's moved to the corresponding system.h headers.

Change-Id: Iebff272f3407a6eaafeb7656ceb0ae9eca3f7cb9
---
 firmware/asm/sh/thread.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 firmware/asm/sh/thread.c

(limited to 'firmware/asm/sh/thread.c')

diff --git a/firmware/asm/sh/thread.c b/firmware/asm/sh/thread.c
new file mode 100644
index 0000000000..e63470c4a1
--- /dev/null
+++ b/firmware/asm/sh/thread.c
@@ -0,0 +1,96 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Ulf Ralberg
+ *
+ * SH processor threading support
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/*---------------------------------------------------------------------------
+ * Start the thread running and terminate it if it returns
+ *---------------------------------------------------------------------------
+ */
+void start_thread(void); /* Provide C access to ASM label */
+static void USED_ATTR __start_thread(void)
+{
+    /* r8 = context */
+    asm volatile (
+    "_start_thread:            \n" /* Start here - no naked attribute */
+        "mov.l  @(4, r8), r0   \n" /* Fetch thread function pointer */
+        "mov.l  @(28, r8), r15 \n" /* Set initial sp */
+        "mov    #0, r1         \n" /* Start the thread */
+        "jsr    @r0            \n"
+        "mov.l  r1, @(36, r8)  \n" /* Clear start address */
+    );
+    thread_exit();
+}
+
+/* Place context pointer in r8 slot, function pointer in r9 slot, and
+ * start_thread pointer in context_start */
+#define THREAD_STARTUP_INIT(core, thread, function) \
+    ({ (thread)->context.r[0] = (uint32_t)&(thread)->context, \
+       (thread)->context.r[1] = (uint32_t)(function),         \
+       (thread)->context.start = (uint32_t)start_thread; })
+
+/*---------------------------------------------------------------------------
+ * Store non-volatile context.
+ *---------------------------------------------------------------------------
+ */
+static inline void store_context(void* addr)
+{
+    asm volatile (
+        "add     #36, %0   \n" /* Start at last reg. By the time routine */
+        "sts.l   pr, @-%0  \n" /* is done, %0 will have the original value */
+        "mov.l   r15,@-%0  \n"
+        "mov.l   r14,@-%0  \n"
+        "mov.l   r13,@-%0  \n"
+        "mov.l   r12,@-%0  \n"
+        "mov.l   r11,@-%0  \n"
+        "mov.l   r10,@-%0  \n"
+        "mov.l   r9, @-%0  \n"
+        "mov.l   r8, @-%0  \n"
+        : : "r" (addr)
+    );
+}
+
+/*---------------------------------------------------------------------------
+ * Load non-volatile context.
+ *---------------------------------------------------------------------------
+ */
+static inline void load_context(const void* addr)
+{
+    asm volatile (
+        "mov.l  @(36, %0), r0 \n" /* Get start address */
+        "tst    r0, r0        \n"
+        "bt     .running      \n" /* NULL -> already running */
+        "jmp    @r0           \n" /* r8 = context */
+    ".running:                \n"
+        "mov.l  @%0+, r8      \n" /* Executes in delay slot and outside it */
+        "mov.l  @%0+, r9      \n"
+        "mov.l  @%0+, r10     \n"
+        "mov.l  @%0+, r11     \n"
+        "mov.l  @%0+, r12     \n"
+        "mov.l  @%0+, r13     \n"
+        "mov.l  @%0+, r14     \n"
+        "mov.l  @%0+, r15     \n"
+        "lds.l  @%0+, pr      \n"
+        : : "r" (addr) : "r0" /* only! */
+    );
+}
+
+
-- 
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