new files submitted by Craig Lebakken (lebakken@minn.net) and Derrick Ostertag

(ostertag@transition.com)

7 files changed, 664 insertions, 0 deletions

diff --git a/c/src/lib/libbsp/a29k/portsw/startup/bspclean.c b/c/src/lib/libbsp/a29k/portsw/startup/bspclean.c
new file mode 100644
index 0000000000..fbd3db563e
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/bspclean.c
@@ -0,0 +1,30 @@
+/*  bsp_cleanup()
+ *
+ *  This routine normally is part of start.s and usually returns
+ *  control to a monitor.
+ *
+ *  INPUT:  NONE
+ *
+ *  OUTPUT: NONE
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+
+#ifndef lint
+static char _sccsid[] = "@(#)bspclean.c 04/08/96     1.1\n";
+#endif
+
+void bsp_cleanup( void )
+{
+}
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/bspstart.c b/c/src/lib/libbsp/a29k/portsw/startup/bspstart.c
new file mode 100644
index 0000000000..1553203875
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/bspstart.c
@@ -0,0 +1,293 @@
+/*  bsp_start()
+ *
+ *  This routine starts the application.  It includes application,
+ *  board, and monitor specific initialization and configuration.
+ *  The generic CPU dependent initialization has been performed
+ *  before this routine is invoked.
+ *
+ *  INPUT:  NONE
+ *
+ *  OUTPUT: NONE
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <bsp.h>
+#include <rtems/libio.h>
+ 
+#include <libcsupport.h>
+ 
+#include <string.h>
+#include <fcntl.h>
+ 
+#ifdef STACK_CHECKER_ON
+#include <stackchk.h>
+#endif
+
+#ifndef lint
+static char _sccsid[] = "@(#)bspstart.c 09/11/96     1.15\n";
+#endif
+
+/*
+ *  The original table from the application and our copy of it with
+ *  some changes.
+ */
+
+extern rtems_configuration_table Configuration;
+
+rtems_configuration_table  BSP_Configuration;
+
+rtems_cpu_table Cpu_table;
+
+char *rtems_progname;
+
+/*      Initialize whatever libc we are using
+ *      called from postdriver hook
+ */
+
+#define HEAP_BLOCK_SIZE (16 * 1024)
+
+rtems_unsigned32        heap_size = 0;
+rtems_unsigned32        heap_start;
+
+void bsp_libc_init()
+{
+    heap_size = 2 * 1024 * 1024; /* allocate a maximum of 2 megabytes for the heap */
+
+    /* allocate all remaining memory to the heap */
+    do {
+       heap_size -= HEAP_BLOCK_SIZE;
+       heap_start = _sysalloc( heap_size );
+    } while ( !heap_start );
+
+    if (!heap_start)
+       rtems_fatal_error_occurred( heap_size );
+
+    if (heap_start & (CPU_ALIGNMENT-1))
+        heap_start = (heap_start + CPU_ALIGNMENT) & ~(CPU_ALIGNMENT-1);
+
+    /*
+     *  The last parameter to RTEMS_Malloc_Initialize is the "chunk"
+     *  size which a multiple of will be requested on each sbrk()
+     *  call by malloc().  A value of 0 indicates that sbrk() should
+     *  not be called to extend the heap.
+     */
+
+    RTEMS_Malloc_Initialize((void *) heap_start, heap_size, 0);
+
+    /*
+     *  Init the RTEMS libio facility to provide UNIX-like system
+     *  calls for use by newlib (ie: provide __open, __close, etc)
+     *  Uses malloc() to get area for the iops, so must be after malloc init
+     */
+
+    rtems_libio_init();
+
+    /*
+     * Set up for the libc handling.
+     */
+
+    if (BSP_Configuration.ticks_per_timeslice > 0)
+        libc_init(1);                /* reentrant if possible */
+    else
+        libc_init(0);                /* non-reentrant */
+
+}
+
+/*
+ *  Function:   bsp_pretasking_hook
+ *  Created:    95/03/10
+ *
+ *  Description:
+ *      BSP pretasking hook.  Called just before drivers are initialized.
+ *      Used to setup libc and install any BSP extensions.
+ *
+ *  NOTES:
+ *      Must not use libc (to do io) from here, since drivers are
+ *      not yet initialized.
+ *
+ */
+ 
+void
+bsp_pretasking_hook(void)
+{
+    bsp_libc_init();
+
+#ifdef STACK_CHECKER_ON
+    /*
+     *  Initialize the stack bounds checker
+     *  We can either turn it on here or from the app.
+     */
+ 
+    Stack_check_Initialize();
+#endif
+ 
+#ifdef RTEMS_DEBUG
+    rtems_debug_enable( RTEMS_DEBUG_ALL_MASK );
+#endif
+}
+ 
+
+/*
+ * After drivers are setup, register some "filenames"
+ * and open stdin, stdout, stderr files
+ *
+ * Newlib will automatically associate the files with these
+ * (it hardcodes the numbers)
+ */
+ 
+void
+bsp_postdriver_hook(void)
+{
+  int stdin_fd, stdout_fd, stderr_fd;
+  int error_code;
+ 
+  error_code = 'S' << 24 | 'T' << 16;
+ 
+  if ((stdin_fd = __open("/dev/console", O_RDONLY, 0)) == -1)
+    rtems_fatal_error_occurred( error_code | 'D' << 8 | '0' );
+ 
+  if ((stdout_fd = __open("/dev/console", O_WRONLY, 0)) == -1)
+    rtems_fatal_error_occurred( error_code | 'D' << 8 | '1' );
+ 
+  if ((stderr_fd = __open("/dev/console", O_WRONLY, 0)) == -1)
+    rtems_fatal_error_occurred( error_code | 'D' << 8 | '2' );
+ 
+  if ((stdin_fd != 0) || (stdout_fd != 1) || (stderr_fd != 2))
+    rtems_fatal_error_occurred( error_code | 'I' << 8 | 'O' );
+
+  printf("allocated %d heap size, %d work space size\n",
+     heap_size, BSP_Configuration.work_space_size);
+  printf(" work space start 0x%x\n",(unsigned int)BSP_Configuration.work_space_start);
+}
+
+
+int bsp_start(
+  int argc,
+  char **argv,
+  char **environp
+)
+{
+  if ((argc > 0) && argv && argv[0])
+    rtems_progname = argv[0];
+  else
+    rtems_progname = "RTEMS";
+
+  /* set the PIA0 register wait states */
+  *(volatile unsigned32 *)0x80000020 = 0x04080000;
+
+  /*
+   *  Allocate the memory for the RTEMS Work Space.  This can come from
+   *  a variety of places: hard coded address, malloc'ed from outside
+   *  RTEMS world (e.g. simulator or primitive memory manager), or (as
+   *  typically done by stock BSPs) by subtracting the required amount
+   *  of work space from the last physical address on the CPU board.
+   */
+
+  /*
+   *  Copy the Configuration Table .. so we can change it
+   */
+
+  BSP_Configuration = Configuration;
+
+  /*
+   * Add 1 region for the RTEMS Malloc
+   */
+
+  BSP_Configuration.RTEMS_api_configuration->maximum_regions++;
+
+  /*
+   * Add 1 extension for newlib libc
+   */
+
+#ifdef RTEMS_NEWLIB
+    BSP_Configuration.maximum_extensions++;
+#endif
+
+  /*
+   * Add 1 extension for newlib libc
+   */
+
+#ifdef RTEMS_NEWLIB
+    BSP_Configuration.maximum_extensions++;
+#endif
+
+#ifdef STACK_CHECKER_ON
+    /*
+     * Add 1 extension for stack checker
+     */
+ 
+    BSP_Configuration.maximum_extensions++;
+#endif
+
+  /*
+   * Tell libio how many fd's we want and allow it to tweak config
+   */
+
+  rtems_libio_config(&BSP_Configuration, BSP_LIBIO_MAX_FDS);
+
+  /*
+   *  Need to "allocate" the memory for the RTEMS Workspace and
+   *  tell the RTEMS configuration where it is.  This memory is
+   *  not malloc'ed.  It is just "pulled from the air".
+   */
+
+  BSP_Configuration.work_space_start = _sysalloc( BSP_Configuration.work_space_size + 512 );
+  if (!BSP_Configuration.work_space_start)
+    rtems_fatal_error_occurred( BSP_Configuration.work_space_size );
+   
+  BSP_Configuration.work_space_start = (void *) ((unsigned int)((char *)BSP_Configuration.work_space_start + CPU_ALIGNMENT) & ~(CPU_ALIGNMENT-1));
+
+  /*
+   *  initialize the CPU table for this BSP
+   */
+
+  /*
+   *  we do not use the pretasking_hook
+   */
+
+  Cpu_table.pretasking_hook = bsp_pretasking_hook;  /* init libc, etc. */
+
+  Cpu_table.predriver_hook = NULL;
+
+  Cpu_table.postdriver_hook = bsp_postdriver_hook;
+
+  Cpu_table.idle_task = NULL;  /* do not override system IDLE task */
+
+  Cpu_table.do_zero_of_workspace = TRUE;
+
+  Cpu_table.interrupt_stack_size = 4096;
+
+  Cpu_table.extra_system_initialization_stack = 0;
+
+  /*
+   *  Don't forget the other CPU Table entries.
+   */
+
+  _settrap( 109,&a29k_enable_sup);
+  _settrap( 110,&a29k_disable_sup);
+  _settrap( 111,&a29k_enable_all_sup);
+  _settrap( 112,&a29k_disable_all_sup);
+  _settrap( 106,&a29k_context_switch_sup);
+  _settrap( 107,&a29k_context_restore_sup);
+  _settrap( 108,&a29k_context_save_sup);
+  _settrap( 105,&a29k_sigdfl_sup);
+
+  /*
+   *  Start RTEMS
+   */
+
+  rtems_initialize_executive( &BSP_Configuration, &Cpu_table );
+
+  bsp_cleanup();
+
+  return 0;
+}
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/iface.c b/c/src/lib/libbsp/a29k/portsw/startup/iface.c
new file mode 100644
index 0000000000..06f49f60bf
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/iface.c
@@ -0,0 +1,96 @@
+/*
+ * glue.c -- all the code to make GCC and the libraries run on
+ *           a target board running RTEMS. These should work with 
+ *           any target which conforms to the RTEMS BSP.
+ *
+ *  $Id$
+ */
+
+#ifndef lint
+static char _sccsid[] = "@(#)iface.c 04/12/96     1.1\n";
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+int
+read(int fd,
+     char *buf,
+     int nbytes)
+{
+    return __read(fd, buf, nbytes);
+}
+
+int
+write(int fd,
+      char *buf,
+      int nbytes)
+{
+    return __write(fd, buf, nbytes);
+}
+
+int
+open(char *buf,
+     int flags,
+     int mode)
+{
+    return __open(buf, flags, mode);
+}
+
+int
+close(int fd)
+{
+    return __close(fd);
+}
+
+/*
+ * isatty -- returns 1 if connected to a terminal device,
+ *           returns 0 if not.
+ */
+int
+isatty(int fd)
+{
+    return __isatty(fd);
+}
+
+/*
+ * lseek -- move read/write pointer. Since a serial port
+ *          is non-seekable, we return an error.
+ */
+off_t
+lseek(int fd,
+      off_t offset,
+      int whence)
+{
+    return __lseek(fd, offset, whence);
+}
+
+/*
+ * fstat -- get status of a file. Since we have no file
+ *          system, we just return an error.
+ */
+int
+fstat(int fd,
+      struct stat *buf)
+{
+    return __fstat(fd, buf);
+}
+
+int
+getpid()
+{
+  return __getpid();
+}
+
+/*
+ * kill -- go out via exit...
+ */
+int
+kill(int pid,
+     int sig)
+{
+    return __kill(pid, sig);
+}
+
+
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/main.c b/c/src/lib/libbsp/a29k/portsw/startup/main.c
new file mode 100644
index 0000000000..c6583852f4
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/main.c
@@ -0,0 +1,39 @@
+/*  main()
+ *
+ *  This is the entry point for the application.  It calls
+ *  the bsp_start routine to the actual dirty work.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+
+#ifndef lint
+static char _sccsid[] = "@(#)main.c 06/30/96     1.2\n";
+#endif
+
+int main(
+  int   argc,
+  char **argv,
+  char **environp
+)
+{
+  bsp_start( argc, argv, environp );
+
+  /*
+   *  May be able to return to the "crt/start.s" code but also
+   *  may not be able to.  Do something here which is board dependent.
+   */
+
+  _exit(0);
+  rtems_fatal_error_occurred( 0 );
+}
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/ramlink b/c/src/lib/libbsp/a29k/portsw/startup/ramlink
new file mode 100644
index 0000000000..8f48e3b395
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/ramlink
@@ -0,0 +1,11 @@
+;@(#)ez030.cmd	1.1 93/04/06 20:00:10, Copyright 1993 AMD.
+;Linker command file header for EZ-030 evaluation board.
+;Usage:  ld29 -c .../29k/lib/ez030.cmd -o ...
+;	 -or-
+;	 hc29 -cmdez030.cmd ...
+;
+;  $Id$
+;
+ALIGN	.text=8192
+ALIGN	.data=8192
+ORDER	.text=0x40005000,!text,!data,!lit,!bss
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/romlink b/c/src/lib/libbsp/a29k/portsw/startup/romlink
new file mode 100644
index 0000000000..043b2ed32c
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/romlink
@@ -0,0 +1,146 @@
+;
+;  $Id$
+;
+;#{
+;# SCCS INFORMATION:
+;# SID		= @(#)sa29200.lnk	4.1;	DLU=95/09/14-11:05:57
+;# Q		= @(#)	Copyright (C) 1995 Advanced Micro Devices, Inc.
+;# Module Type	= @(#)	OSBOOT/DBG_CORE absolute liker file (AMD-EPD-29K, AMIR)
+;# SCCS Path	= %P\%
+;# SCCS File	= %F\%
+;# FileName	= sa29200.lnk
+;# SCCS ID	= 4.1
+;# Date Update	= 14 Sep 1995, (DLU=95/09/14-11:05:57)
+;# Date Extract	= 12 Oct 1995, (DLE=95/10/12-16:27:31)
+;#}
+; @(#)sa29200.lnk	3.6 94/08/22 11:58:54, Srini, AMD.
+; This is the linker command file used to bind the inrementally linked
+; osboot.o module to a memory map. This also defines some link-time constants
+; used in the code. These constants are genral for all 29K family members.
+; You only need to customize, if necessary, the definitions that affect
+; your target processor, and leave the rest alone.
+; The default values in this file are for binding osboot.o for use with
+; SA29200 stand-alone board with the -29200/-29205 option.
+;
+; Order the code segments according to the memory map structure.
+; The defaul OSBOOT has only .text and .bss sections. You need to ORDER
+; other sections of your applications that are not included below.
+; We use separate ORDER statements below to distinguish the two memory
+; regions used. The text section is bound to ROM memory region, and the
+; data region to RAM memory space.
+; MAKE SURE to order the BSS section at the very end. This is because the
+; BSS section size could get adjusted after linking with raminit.o (produced
+; by romcoff utility) or other initialization routines. This change in size
+; could affect the offsets used by the program to refer to the remaining data
+; sections that follow BSS.
+ALIGN	ProcInit=16
+ORDER	Reset=0x0
+ORDER	ProcInit,OsbText,.text,!text
+ORDER	.lit,!lit
+ORDER	vectable=0x40000000
+ORDER	msg_data=0x40000400
+ORDER	.data,!data
+ORDER	OsbBss,dbg_030,dbg_bss,cfg_bss,.bss,!bss
+ORDER	HeapBase
+ORDER	.comment
+; For Stand-Alone application out of ROM use the ORDER statements below:
+; For Stand-Alone application out of RAM use the ORDER statement below:
+;ORDER	Reset=0x40010000,ProcInit,OsbText,.text,!text,.lit,!lit,.data,!data,msg_data,dbg_dat,.bss,!bss,HeapBase,.comment
+;
+; definitions of link time constants used in code.
+;
+; Definition of the initial value of CPS register.
+; The value below is for an Am29200 processor. It sets TU, SM,DI, DA,IM fields
+; bits in the register. You may modify it to suit your target environment.
+; Like, changing the IM field for instance. IM is 0x11 by default enabling
+; all INTR[0-3] lines.
+;public	_init_CPS=0x87F
+public  _init_CPS=0x20813
+;public  _init_CPS=0x2081F
+;public  _init_CPS=0x081F
+; Define the memory map in general values. The code - except for simulators -
+; configures the external RAM at run-time and updates the DMemSize value.
+; DMemStart and DMemSize are the most important values below. DMemStart is
+; used to initialize the vector base address register (VAB). And DMemSize
+; is used to find the highest addressable data memory to place the register
+; and memory stacks. Remember, DMemSize is configured at run-time for hardware
+; targets and updated.
+public	VectorBaseAddress=0x40000000
+public	IMemStart=0x0000000
+public	IMemSize=0xfffff
+public	DMemStart=0x40000000
+#public	DMemStart=0x100000
+public	DMemSize=0xfffff
+#public	DMemSize=0x17ffff
+#public	DMemSize=0x3fffffff
+public	RMemStart=0x0
+public	RMemSize=0xfffff
+public	EnableDRAMSizing=1
+;
+; For the 29K Microcontrollers, you need to define the ROM Control register
+; value (RMCT_VALUE), the ROM Configuration register value (RMCF_VALUE), and
+; the DRAM Control register value (DRCT_VALUE) based on DMemSize specified
+; above. This could be overwritten in software targets such as the simulator.
+; ROM and RAM Control registers. ROM COnfiguration. (not valid for Am2900X,
+; Am29050, and Am2903X processors)
+; The DRAM REFRATE value (in DRCT) must be specified here. To disable
+; DRAM refreshing (on a system with no DRAM), set REFRATE field in DRCT
+; to zero. Otherwise, set it to the desired frequency. The default is 0xFF
+; The default values in this file are for Am2920X processors.
+;public	RMCT_VALUE=0x03030303
+;public	DRCT_VALUE=0x888800FF
+;public	RMCF_VALUE=0x00f8f8f8
+;
+public	RMCT_VALUE=0x4a424300
+public	DRCT_VALUE=0xccc000f0
+public	RMCF_VALUE=0x011121ff
+;
+;
+; Execute trap handlers from ROM? If your trap handlers are in ROM space,
+; then set _TRAPINROM to TWO (0x2). It is used to modify the tarp vector
+; address installed to set the R bit when fetched. If the trap handlers in
+; ROM or if there is no ROM-space (no RE bit in CPS), set _TRAPINROM to ZERO.
+; The default in this file is for SA29200 board and _TRAPINROM is set to ZERO.
+public	_TRAPINROM=0
+;
+; Define the processor clock frequencies. These values are used by the HIF
+; kernel to provide some HIF services.
+public	TicksPerMillisecond=16000
+public	ClockFrequency=16000000
+;
+; There are some C functions which are not leaf functions. However, they are
+; no expected to spill or fill registers. We ensure that by setting up a
+; pseudo register stack before calling those functions. The code generated
+; for those functions however do have the prologue and epilogue which refer
+; to the symbols V_SPILL and V_FILL. The linker does not know about these
+; symbols. So we define it here so that it does not complain.
+; If you use the hc29 compiler driver to link the objects it will warn that
+; the definitions here are already internally defined. You
+; can use hc29 with -nocrt0 option to do the linking for linear memory spaces.
+; public	V_SPILL=64
+; public	V_FILL=65
+;
+; Set the UART debug/monitor port serial communications baud rate.
+;
+public UCLK=32000000
+; INITBAUD defines the cold start baud rate. This is the baud rate 
+; the monitor would use when powered up. This can be overridden by
+; defining BAUDRATE on the assembler/compiler command line.
+public INITBAUD=9600
+;
+; Is there a SCC 8530 on the target?
+; If there is an 8530 SC on target, define the symbols below appropriately.
+; The routines in scc8530.s use these values to access the registers of
+; SCC and program it. The default values are for EZ030 target.
+; Baudrate can be specified on the command-line to override the default
+; baud rate defined in scc8530.s.
+; scc channel A control
+;public	SCC8530_CHA_CONTROL=0xC0000007
+; scc channel B control
+;public	SCC8530_CHB_CONTROL=0xC0000003
+; scc channel A data
+;public	SCC8530_CHA_DATA=0xC000000F
+; scc channel B data
+;public	SCC8530_CHB_DATA=0xC000000B
+; scc baud clock generator
+;public	SCC8530_BAUD_CLK_ENBL=3
diff --git a/c/src/lib/libbsp/a29k/portsw/startup/setvec.c b/c/src/lib/libbsp/a29k/portsw/startup/setvec.c
new file mode 100644
index 0000000000..6adbc4e72a
--- /dev/null
+++ b/c/src/lib/libbsp/a29k/portsw/startup/setvec.c
@@ -0,0 +1,49 @@
+/*  set_vector
+ *
+ *  This routine installs an interrupt vector on the target Board/CPU.
+ *  This routine is allowed to be as board dependent as necessary.
+ *
+ *  INPUT:
+ *    handler - interrupt handler entry point
+ *    vector  - vector number
+ *    type    - 0 indicates raw hardware connect
+ *              1 indicates RTEMS interrupt connect
+ *
+ *  RETURNS:
+ *    address of previous interrupt handler
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+
+#ifndef lint
+static char _sccsid[] = "@(#)setvec.c 06/30/96     1.2\n";
+#endif
+
+no_cpu_isr_entry set_vector(                    /* returns old vector */
+  rtems_isr_entry     handler,                  /* isr routine        */
+  rtems_vector_number vector,                   /* vector number      */
+  int                 type                      /* RTEMS or RAW intr  */
+)
+{
+  no_cpu_isr_entry previous_isr;
+
+  if ( type )
+    rtems_interrupt_catch( handler, vector, (rtems_isr_entry *) &previous_isr );
+  else {
+    /* XXX: install non-RTEMS ISR as "raw" interupt */
+    _settrap( vector, handler );
+  }
+  return previous_isr;
+}
+