/* dlentry.s 1.0 - 95/08/08
*
* This file contains the entry veneer for RTEMS programs
* stored in Papyrus' flash ROM.
*
* Author: Andrew Bray <andy@i-cubed.demon.co.uk>
*
* COPYRIGHT (c) 1995 by i-cubed ltd.
*
* 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.
*
* $Id$
*/
#include "asm.h"
/*
* The Papyrus ELF link scripts support three special sections:
* .entry The actual entry point, this must contain less
* than 256 bytes of code/data to fit below the
* .vectors section. This always preceeds any other
* code or data.
* .vectors The section containing the interrupt entry veneers.
* .entry2 Any code overflowing from .entry
* .descriptors The PowerOpen function indirection blocks.
*/
/*
* Flash sections are linked in the following order:
* .entry
* .vectors
* .entry2
* .text
* .descriptors
* .data
* .bss
* usually starting from 0xFFF00000.
*
* The initial stack is set to run BELOW the final location of
* the initialised data.
*
* All the entry veneer has to do is to copy the initialised data
* to its final location and clear the BSS.
*/
/*
* GDB likes to have debugging information for the entry veneer.
* Here is some DWARF information.
*/
#if PPC_ASM == PPC_ASM_ELF
.section .entry,"ax",@progbits
.L_text_b:
.L_LC1:
.previous
.section .debug_sfnames
.L_sfnames_b:
.byte "/home/andy/powerpc/rtems-3.2.0/c/src/lib/libcpu/ppc/ppc403/flashentry/"
.byte 0
.L_F0:
.byte "flashentry.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 "flash_entry"
.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 "flashentry.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 "/home/andy/powerpc/rtems-3.2.0/c/src/lib/libcpu/ppc/ppc403/dlentry/"
.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 "flash_entry"
.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
#endif
/*-------------------------------------------------------------------------------
* ROM Vector area.
*------------------------------------------------------------------------------*/
#if PPC_ASM == PPC_ASM_ELF
.section .entry
#else
.csect .text[PR]
#endif
PUBLIC_VAR (flash_entry)
SYM (flash_entry):
bl .startup
base_addr:
/*-------------------------------------------------------------------------------
* Parameters from linker
*------------------------------------------------------------------------------*/
toc_pointer:
#if PPC_ASM == PPC_ASM_ELF
.long s.got
#else
.long TOC[tc0]
#endif
text_length:
.long t.size
text_addr:
.long t.start
data_length:
.long copy.size
data_addr:
.long copy.dest
bss_length:
.long bss.size
bss_addr:
.long bss.start
/*-------------------------------------------------------------------------------
* Reset_entry.
*------------------------------------------------------------------------------*/
.startup:
/* Get start address */
mflr r1
/* Assume Bank regs set up..., cache etc. */
/*-----------------------------------------------------------------------
* Check the DRAM where STACK+ DATA+ BBS will be placed. If this is OK
* we will return here.
*----------------------------------------------------------------------*/
bl rom2ram
/*-----------------------------------------------------------------------
* Enable two 128MB cachable regions.
*----------------------------------------------------------------------*/
addis r2,r0,0x8000
addi r2,r2,0x0001
mticcr r2
mtdccr r2
/*-----------------------------------------------------------------------
* C_setup.
*----------------------------------------------------------------------*/
lwz r2,toc_pointer-base_addr(r1) /* set r2 to toc */
lwz r1,data_addr-base_addr(r1) /* set r1 to data_addr */
addi r1,r1,-56 /* start stack at data_addr - 56 */
addi r3,r0,0x0 /* clear r3 */
stw r3, 0(r1) /* Clear stack chain */
stw r3, 4(r1)
stw r3, 8(r1)
stw r3, 12(r1)
.extern .main
b .main /* call the first C routine */
/*-------------------------------------------------------------------------------
* Rom2ram.
*------------------------------------------------------------------------------*/
rom2ram:
lwz r2,data_addr-base_addr(r1) /* start of data set by loader */
lwz r3,data_length-base_addr(r1) /* data length */
rlwinm r3,r3,30,0x3FFFFFFF /* form length/4 */
mtctr r3 /* set ctr reg */
/*-----------------------------------------------------------------------
* Calculate offset of data in image.
*----------------------------------------------------------------------*/
lwz r5,text_length-base_addr(r1) /* get text length */
lwz r4,text_addr-base_addr(r1) /* get text length */
add r4,r4,r5 /* r4 = data pointer */
move_data:
lswi r6,r4,0x4 /* load r6 */
stswi r6,r2,0x4 /* store r6 */
addi r4,r4,0x4 /* update r4 */
addi r2,r2,0x4 /* update r2 */
bdnz move_data /* decrement counter and loop */
/*-----------------------------------------------------------------------
* Data move finished, zero out bss.
*----------------------------------------------------------------------*/
lwz r2,bss_addr-base_addr(r1) /* start of bss set by loader */
lwz r3,bss_length-base_addr(r1) /* bss length */
rlwinm. r3,r3,30,0x3FFFFFFF /* form length/4 */
beqlr /* no bss */
mtctr r3 /* set ctr reg */
xor r6,r6,r6 /* r6 = 0 */
clear_bss:
stswi r6,r2,0x4 /* store r6 */
addi r3,r2,0x4 /* update r2 */
bdnz clear_bss /* decrement counter and loop */
blr /* return */
.L_text_e:
#if PPC_ABI == PPC_ABI_POWEROPEN
DESCRIPTOR (startup)
#endif
