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/*
* This file contains the entry veneer for RTEMS programs on the Intec
* SS555 board. It jumps to the BSP which is responsible for performing
* all remaining initialization.
*/
/*
* This file is based on several others:
*
* (1) start360.s from the gen68360 BSP by
* W. Eric Norum (eric@skatter.usask.ca)
* with the following copyright and license:
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may in
* the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*
* (2) start.s for the eth_comm port by
* Jay Monkman (jmonkman@fracsa.com),
* which itself is based on the
*
* (3) dlentry.s for the Papyrus BSP, written by:
* Andrew Bray <andy@i-cubed.co.uk>
* with the following copyright and license:
*
* COPYRIGHT (c) 1995 by i-cubed ltd.
*
* (4) start860.S for the MBX821/MBX860, written by:
* Darlene A. Stewart <darlene.stewart@iit.nrc.ca>
* Copyright (c) 1999, National Research Council of Canada
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of i-cubed limited not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* i-cubed limited makes no representations about the suitability
* of this software for any purpose.
*
* (5) Modifications (for MBX8xx) of respective RTEMS files:
* Copyright (c) 1999, National Research Council of Canada
*
* SS555 port sponsored by Defence Research and Development Canada - Suffield
* Copyright (C) 2004, Real-Time Systems Inc. (querbach@realtime.bc.ca)
*/
#include <rtems/asm.h>
#include <rtems/powerpc/registers.h>
#include <bsp.h>
/*
* The initial stack is set to the top of the internal RAM.
*
* All the entry veneer has to do is to clear the .bss section and copy the
* initializers into the .data section.
*/
/*
* GDB likes to have debugging information for the entry veneer.
* Play compiler and provide some DWARF information.
*
* CHANGE TO SUIT YOUR SETUP!
*/
.section .entry,"ax",@progbits
.L_text_b:
.L_LC1:
.previous
.section .debug_sfnames
.L_sfnames_b:
.byte "rtems/c/src/lib/libbsp/powerpc/ss555/startup/"
.byte 0
.L_F0:
.byte "start.S"
.byte 0
.previous
.section .line
.L_line_b:
.4byte .L_line_e-.L_line_b
.4byte .L_text_b
.L_LE1:
.L_line_last:
.4byte 0x0
.2byte 0xffff
.4byte .L_text_e-.L_text_b
.L_line_e:
.previous
.section .debug_srcinfo
.L_srcinfo_b:
.4byte .L_line_b
.4byte .L_sfnames_b
.4byte .L_text_b
.4byte .L_text_e
.4byte 0xffffffff
.4byte .L_LE1-.L_line_b
.4byte .L_F0-.L_sfnames_b
.4byte .L_line_last-.L_line_b
.4byte 0xffffffff
.previous
.section .debug_pubnames
.4byte .L_debug_b
.4byte .L_P0
.byte "start"
.byte 0
.4byte 0x0
.byte 0
.previous
.section .debug_aranges
.4byte .L_debug_b
.4byte .L_text_b
.4byte .L_text_e-.L_text_b
.4byte 0
.4byte 0
.4byte 0
.4byte 0
.4byte 0
.4byte 0
.4byte 0x0
.4byte 0x0
.previous
.section .debug
.L_debug_b:
.L_D1:
.4byte .L_D1_e-.L_D1
.2byte 0x11 /* TAG_compile_unit */
.2byte 0x12 /* AT_sibling */
.4byte .L_D2
.2byte 0x38 /* AT_name */
.byte "start.S"
.byte 0
.2byte 0x258 /* AT_producer */
.byte "GAS 2.5.2"
.byte 0
.2byte 0x111 /* AT_low_pc */
.4byte .L_text_b
.2byte 0x121 /* AT_high_pc */
.4byte .L_text_e
.2byte 0x106 /* AT_stmt_list */
.4byte .L_line_b
.2byte 0x1b8 /* AT_comp_dir */
.byte "rtems/c/src/lib/libbsp/powerpc/ss555/startup/"
.byte 0
.2byte 0x8006 /* AT_sf_names */
.4byte .L_sfnames_b
.2byte 0x8016 /* AT_src_info */
.4byte .L_srcinfo_b
.L_D1_e:
.L_P0:
.L_D3:
.4byte .L_D3_e-.L_D3
.2byte 0x6 /* TAG_global_subroutine */
.2byte 0x12 /* AT_sibling */
.4byte .L_D4
.2byte 0x38 /* AT_name */
.byte "start"
.byte 0
.2byte 0x278 /* AT_prototyped */
.byte 0
.2byte 0x111 /* AT_low_pc */
.4byte .L_text_b
.2byte 0x121 /* AT_high_pc */
.4byte .L_text_e
.2byte 0x8041 /* AT_body_begin */
.4byte .L_text_b
.2byte 0x8051 /* AT_body_end */
.4byte .L_text_e
.L_D3_e:
.L_D4:
.4byte .L_D4_e-.L_D4
.align 2
.L_D4_e:
.L_D2:
.previous
/*
* Tell C's eabi-ctor's that we have an atexit function,
* and that it is to register __do_global_dtors.
*/
EXTERN_PROC(atexit)
PUBLIC_VAR(__atexit)
.section ".sdata","aw"
.align 2
SYM(__atexit):
EXT_PROC_REF(atexit)@fixup
.previous
.section ".fixup","aw"
.align 2
EXT_SYM_REF(__atexit)
.previous
/* That should do it */
/*
* Put the entry point in its own section. That way, we can guarantee
* to put it first in the .text section in the linker script.
*/
.section .entry
PUBLIC_VAR (start)
SYM(start):
bl .startup /* or bl .spin */
base_addr:
/*
* Parameters from linker
*/
stack_top:
.long initStackPtr
toc_pointer:
.long __GOT_START__
bss_length:
.long bss.size
bss_addr:
.long bss.start
data_length:
.long data.size
data_addr:
.long data.start
contents_addr:
.long data.contents.start
PUBLIC_VAR (text_addr)
text_addr:
.long text.start
PUBLIC_VAR (text_length)
text_length:
.long text.size
/*
* Spin, if necessary, to acquire control from debugger (CodeWarrior).
*/
spin:
.long 0x0001
.spin:
lis r3, spin@ha
lwz r3, spin@l(r3)
cmpwi r3, 0x1
beq .spin
/*
* Initialization code
*/
.startup:
/* Capture address of linker parameters. */
mflr r3
/* Set initial stack pointer to end of internal RAM - 56. */
lwz r1, stack_top-base_addr(r3)
addi r1, r1, -56
/* Initialize essential registers. */
bl initregs
/* Set TOC pointer */
lwz r2, toc_pointer-base_addr(r3)
/* Initialize the memory mapped MPC555 registers (done in C). */
EXTERN_PROC (_InitSS555)
bl PROC (_InitSS555)
/* Clear the .bss section. */
bl bssclr
/* Copy initializers into the .data section */
bl datacopy
/* Enable floating point, since gcc sometimes uses the floating
* point registers for data moves, even if the C source code doesn't
* include floating point operations.
*/
mfmsr r0
ori r0, r0, MSR_FP
mtmsr r0
/* Start system. */
li r3, 0 /* command line */
EXTERN_PROC (boot_card)
bl PROC (boot_card) /* call the first C routine */
/* We should never return from boot_card, but in case we do ... */
/* The next instructions are dependent on your runtime environment. */
stop_here:
b stop_here
/*
* datacopy - copy initializers into .data section
*/
datacopy:
lis r3, base_addr@ha /* point to linker data */
addi r3, r3, base_addr@l
lwz r4, contents_addr-base_addr(r3) /* .data contents in ROM */
lwz r5, data_addr-base_addr(r3) /* .data section in RAM */
lwz r6, data_length-base_addr(r3) /* length of .data */
rlwinm. r6, r6, 30, 0x3FFFFFFF /* form length / 4 */
beqlr /* no .data - return */
mtctr r6 /* set ctr reg */
dc1:
lwz r6, 0(r4) /* get word */
stw r6, 0(r5) /* store word */
addi r4, r4, 0x4 /* next source */
addi r5, r5, 0x4 /* next target */
bdnz dc1 /* dec counter and loop */
blr /* return */
/*
* bssclr - zero out bss
*/
bssclr:
lis r3, base_addr@ha /* point to linker data */
addi r3, r3, base_addr@l
lwz r4, bss_addr-base_addr(r3) /* Start of bss */
lwz r5, bss_length-base_addr(r3) /* Length of bss */
rlwinm. r5, r5, 30, 0x3FFFFFFF /* form length/4 */
beqlr /* no bss - return */
mtctr r5 /* set ctr reg */
li r5, 0x0000 /* r5 = 0 */
clear_bss:
stw r5, 0(r4) /* store r6 */
addi r4, r4, 0x4 /* update r4 */
bdnz clear_bss /* dec counter and loop */
blr /* return */
/*
* initregs
* Initialize the MSR and basic core PowerPC registers
*
* Register usage:
* r0 - scratch
*/
initregs:
/*
* Set the processor for big-endian mode, exceptions vectored to
* 0x000n_nnnn, no execution tracing, machine check exceptions
* enabled, floating-point not available, supervisor priviledge
* level, external interrupts disabled, power management disabled
* (normal operation mode).
*/
li r0, 0x1000 /* MSR_ME */
mtmsr r0 /* Context-synchronizing */
isync
/*
* Clear the exception handling registers.
*/
li r0, 0x0000
mtdar r0
mtspr sprg0, r0
mtspr sprg1, r0
mtspr sprg2, r0
mtspr sprg3, r0
mtspr srr0, r0
mtspr srr1, r0
mr r6, r0
mr r7, r0
mr r8, r0
mr r9, r0
mr r10, r0
mr r11, r0
mr r12, r0
mr r13, r0
mr r14, r0
mr r15, r0
mr r16, r0
mr r17, r0
mr r18, r0
mr r19, r0
mr r20, r0
mr r21, r0
mr r22, r0
mr r23, r0
mr r24, r0
mr r25, r0
mr r26, r0
mr r27, r0
mr r28, r0
mr r29, r0
mr r30, r0
mr r31, r0
blr /* return */
.L_text_e:
|
