diff packages/hal/i386/arch/current/src/hal_misc.c @ 2:443894e2e912 ecos-v1_2_1-release

Block commit of eCos version 1.2.1
author jlarmour
date Tue, 11 May 1999 12:24:34 +0000
parents
children c38311975d4f
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+++ b/packages/hal/i386/arch/current/src/hal_misc.c
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+//===========================================================================
+//
+//      hal_misc.c
+//
+//      HAL miscellaneous functions
+//
+//===========================================================================
+//####COPYRIGHTBEGIN####
+//
+// -------------------------------------------
+// The contents of this file are subject to the Cygnus eCos Public License
+// Version 1.0 (the "License"); you may not use this file except in
+// compliance with the License.  You may obtain a copy of the License at
+// http://sourceware.cygnus.com/ecos
+//
+// Software distributed under the License is distributed on an "AS IS"
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the
+// License for the specific language governing rights and limitations under
+// the License.
+//
+// The Original Code is eCos - Embedded Cygnus Operating System, released
+// October 31, 1998.
+//
+// The Initial Developer of the Original Code is Cygnus.  Portions created
+// by Cygnus are Copyright (C) 1998,1999 Cygnus Solutions.  All Rights Reserved.
+// -------------------------------------------
+//
+//####COPYRIGHTEND####
+//===========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):    nickg
+// Contributors: proven
+// Date:        1999-02-20
+// Purpose:     HAL miscellaneous functions
+// Description: This file contains miscellaneous functions provided by the
+//              HAL.
+//
+//####DESCRIPTIONEND####
+//
+//===========================================================================
+
+#include <pkgconf/hal.h>
+
+#include <cyg/infra/cyg_type.h>
+
+#include <cyg/hal/hal_arch.h>
+
+//---------------------------------------------------------------------------
+
+#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
+cyg_bool cyg_hal_stop_constructors;
+#endif
+
+typedef void (*pfunc) (void);
+extern pfunc __CTOR_LIST__[];
+extern pfunc __CTOR_END__[];
+
+void
+cyg_hal_invoke_constructors (void)
+{
+#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
+    static pfunc *p = &__CTOR_END__[-1];
+    
+    cyg_hal_stop_constructors = 0;
+    for (; p >= __CTOR_LIST__; p--) {
+        (*p) ();
+        if (cyg_hal_stop_constructors) {
+            p--;
+            break;
+        }
+    }
+#else
+    pfunc *p;
+
+    for (p = &__CTOR_END__[-1]; p >= __CTOR_LIST__; p--)
+        (*p) ();
+#endif
+}
+
+//---------------------------------------------------------------------------
+// Determine the index of the ls bit of the supplied mask.
+
+cyg_uint32
+hal_lsbit_index(cyg_uint32 mask)
+{
+    cyg_uint32 n = mask;
+
+    static const signed char tab[64] =
+    { -1, 0, 1, 12, 2, 6, 0, 13, 3, 0, 7, 0, 0, 0, 0, 14, 10,
+      4, 0, 0, 8, 0, 0, 25, 0, 0, 0, 0, 0, 21, 27 , 15, 31, 11,
+      5, 0, 0, 0, 0, 0, 9, 0, 0, 24, 0, 0 , 20, 26, 30, 0, 0, 0,
+      0, 23, 0, 19, 29, 0, 22, 18, 28, 17, 16, 0
+    };
+
+    n &= ~(n-1UL);
+    n = (n<<16)-n;
+    n = (n<<6)+n;
+    n = (n<<4)+n;
+
+    return tab[n>>26];
+}
+
+//---------------------------------------------------------------------------
+// Determine the index of the ms bit of the supplied mask.
+
+cyg_uint32
+hal_msbit_index(cyg_uint32 mask)
+{
+    cyg_uint32 x = mask;    
+    cyg_uint32 w;
+
+    // Phase 1: make word with all ones from that one to the right.
+    x |= x >> 16;
+    x |= x >> 8;
+    x |= x >> 4;
+    x |= x >> 2;
+    x |= x >> 1;
+
+    // Phase 2: calculate number of "1" bits in the word.
+    w = (x & 0x55555555) + ((x >> 1) & 0x55555555);
+    w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
+    w = w + (w >> 4);
+    w = (w & 0x000F000F) + ((w >> 8) & 0x000F000F);
+    return (cyg_uint32)((w + (w >> 16)) & 0xFF);
+
+}
+
+//---------------------------------------------------------------------------
+// First level C exception handler.
+
+void
+cyg_hal_exception_handler(HAL_SavedRegisters *regs)
+{
+    // We should decode the vector and pass a more appropriate
+    // value as the second argument. For now we simply pass a
+    // pointer to the saved registers. We should also divert
+    // breakpoint and other debug vectors into the debug stubs.
+
+#ifdef CYGIMP_EXCEPTIONS
+
+    cyg_hal_deliver_exception( regs->vector>>8, (CYG_ADDRWORD)regs );
+
+#endif
+    
+    return;
+}
+
+//---------------------------------------------------------------------------
+// End of hal_misc.c