source: rtems/c/src/lib/libbsp/powerpc/papyrus/dlentry/dlentry.S @ eba2e4f

4.104.114.84.95
Last change on this file since eba2e4f was 15c48f4c, checked in by Joel Sherrill <joel.sherrill@…>, on Aug 2, 2000 at 4:30:57 PM

Properly pass argc, argc, and environp to boot_card.

  • Property mode set to 100644
File size: 6.6 KB
Line 
1/*  dlentry.s   1.0 - 95/08/08
2 *
3 *  This file contains the entry veneer for RTEMS programs
4 *  downloaded to Papyrus.
5 *
6 *  Author:     Andrew Bray <andy@i-cubed.co.uk>
7 *
8 *  COPYRIGHT (c) 1995 by i-cubed ltd.
9 *
10 *  To anyone who acknowledges that this file is provided "AS IS"
11 *  without any express or implied warranty:
12 *      permission to use, copy, modify, and distribute this file
13 *      for any purpose is hereby granted without fee, provided that
14 *      the above copyright notice and this notice appears in all
15 *      copies, and that the name of i-cubed limited not be used in
16 *      advertising or publicity pertaining to distribution of the
17 *      software without specific, written prior permission.
18 *      i-cubed limited makes no representations about the suitability
19 *      of this software for any purpose.
20 *
21 *  $Id$
22 */
23
24#include "asm.h"
25
26/*
27 *  The Papyrus ELF link scripts support three special sections:
28 *    .entry    The actual entry point, this must contain less
29 *              than 256 bytes of code/data to fit below the
30 *              .vectors section.  This always preceeds any other
31 *              code or data.
32 *    .vectors  The section containing the interrupt entry veneers.
33 *    .entry2   Any code overflowing from .entry
34 *    .descriptors The PowerOpen function indirection blocks.
35 */
36
37/*
38 *  Downloaded code loads the vectors separately to 0x00000100,
39 *  so .entry can be over 256 bytes.
40 *
41 *  The other sections are linked in the following order:
42 *    .entry
43 *    .entry2
44 *    .text
45 *    .descriptors
46 *    .data
47 *    .bss
48 *  usually starting from 0x00020000.
49 *
50 *  The initial stack is set to run BELOW the code base address.
51 *
52 *  All the entry veneer has to do is to clear the BSS.
53 */
54
55/*
56 *  GDB likes to have debugging information for the entry veneer.
57 *  Here is some DWARF information.
58 */
59
60#if PPC_ASM == PPC_ASM_ELF
61        .section .entry,"ax",@progbits
62.L_text_b:
63.L_LC1:
64        .previous
65
66.section        .debug_sfnames
67.L_sfnames_b:
68        .byte "/home/andy/powerpc/rtems-3.2.0/c/src/lib/libcpu/ppc/ppc403/dlentry/"
69        .byte 0
70.L_F0:
71        .byte "dlentry.s"
72        .byte 0
73        .previous
74
75.section        .line
76.L_line_b:
77        .4byte  .L_line_e-.L_line_b
78        .4byte  .L_text_b
79.L_LE1:
80.L_line_last:
81        .4byte  0x0
82        .2byte  0xffff
83        .4byte  .L_text_e-.L_text_b
84.L_line_e:
85        .previous
86
87.section        .debug_srcinfo
88.L_srcinfo_b:
89        .4byte  .L_line_b
90        .4byte  .L_sfnames_b
91        .4byte  .L_text_b
92        .4byte  .L_text_e
93        .4byte  0xffffffff
94        .4byte  .L_LE1-.L_line_b
95        .4byte  .L_F0-.L_sfnames_b
96        .4byte  .L_line_last-.L_line_b
97        .4byte  0xffffffff
98        .previous
99
100.section        .debug_pubnames
101        .4byte  .L_debug_b
102        .4byte  .L_P0
103        .byte "download_entry"
104        .byte 0
105        .4byte  0x0
106        .byte 0
107        .previous
108
109.section        .debug_aranges
110        .4byte  .L_debug_b
111        .4byte  .L_text_b
112        .4byte  .L_text_e-.L_text_b
113        .4byte  0
114        .4byte  0
115        .4byte  0
116        .4byte  0
117        .4byte  0
118        .4byte  0
119        .4byte  0x0
120        .4byte  0x0
121        .previous
122
123.section        .debug
124.L_debug_b:
125.L_D1:
126        .4byte  .L_D1_e-.L_D1
127        .2byte  0x11    /* TAG_compile_unit */
128        .2byte  0x12    /* AT_sibling */
129        .4byte  .L_D2
130        .2byte  0x38    /* AT_name */
131        .byte "dlentry.s"
132        .byte 0
133        .2byte  0x258   /* AT_producer */
134        .byte "GAS 2.5.2"
135        .byte 0
136        .2byte  0x111   /* AT_low_pc */
137        .4byte  .L_text_b
138        .2byte  0x121   /* AT_high_pc */
139        .4byte  .L_text_e
140        .2byte  0x106   /* AT_stmt_list */
141        .4byte  .L_line_b
142        .2byte  0x1b8   /* AT_comp_dir */
143        .byte "/home/andy/powerpc/rtems-3.2.0/c/src/lib/libcpu/ppc/ppc403/dlentry/"
144        .byte 0
145        .2byte  0x8006  /* AT_sf_names */
146        .4byte  .L_sfnames_b
147        .2byte  0x8016  /* AT_src_info */
148        .4byte  .L_srcinfo_b
149.L_D1_e:
150.L_P0:
151.L_D3:
152        .4byte  .L_D3_e-.L_D3
153        .2byte  0x6     /* TAG_global_subroutine */
154        .2byte  0x12    /* AT_sibling */
155        .4byte  .L_D4
156        .2byte  0x38    /* AT_name */
157        .byte "download_entry"
158        .byte 0
159        .2byte  0x278   /* AT_prototyped */
160        .byte 0
161        .2byte  0x111   /* AT_low_pc */
162        .4byte  .L_text_b
163        .2byte  0x121   /* AT_high_pc */
164        .4byte  .L_text_e
165        .2byte  0x8041  /* AT_body_begin */
166        .4byte  .L_text_b
167        .2byte  0x8051  /* AT_body_end */
168        .4byte  .L_text_e
169.L_D3_e:
170
171.L_D4:
172        .4byte  .L_D4_e-.L_D4
173        .align 2
174.L_D4_e:
175.L_D2:
176        .previous
177#endif
178                               
179/*-------------------------------------------------------------------------------
180 * ROM Vector area.
181 *------------------------------------------------------------------------------*/
182#if PPC_ASM == PPC_ASM_ELF
183        .section .entry
184#else
185        .csect .text[PR]
186#endif
187
188        PUBLIC_VAR (download_entry)
189SYM(download_entry):
190        bl      .startup
191base_addr:     
192
193/*-------------------------------------------------------------------------------
194 * Parameters from linker
195 *------------------------------------------------------------------------------*/
196toc_pointer:   
197#if PPC_ASM == PPC_ASM_ELF
198        .long   s.got
199#else
200        .long   TOC[tc0]
201#endif
202bss_length:     
203        .long   bss.size
204bss_addr:       
205        .long   bss.start
206/*-------------------------------------------------------------------------------
207 * Reset_entry.
208 *------------------------------------------------------------------------------*/
209.startup:
210        /* Get start address, stack grows down from here... */
211        mflr    r1
212       
213        /* Assume Bank regs set up..., cache etc. */
214        bl      bssclr
215
216        /*-----------------------------------------------------------------------
217         * C_setup.
218         *----------------------------------------------------------------------*/
219        lwz     r2,toc_pointer-base_addr(r1)       /* set r2 to toc */
220        addi    r1,r1,-56-4              /* start stack at text_addr - 56 */
221        addi    r3,r0,0x0                /* clear r3 */
222        stw     r3, 0(r1)                /* Clear stack chain */
223        stw     r3, 4(r1)
224        stw     r3, 8(r1)
225        stw     r3, 12(r1)
226        lis     r5,environ@ha
227        la      r5,environ@l(r5)        /* environp */
228        li      r4, 0                   /* argv */
229        li      r3, 0                   /* argc */
230        .extern SYM (boot_card)
231        b       SYM (boot_card)          /* call the first C routine */
232
233/*-------------------------------------------------------------------------------
234 * bssclr.
235 *------------------------------------------------------------------------------*/
236bssclr:
237        /*-----------------------------------------------------------------------
238         * Data move finished, zero out bss.
239         *----------------------------------------------------------------------*/
240        lwz     r2,bss_addr-base_addr(r1)         /* start of bss set by loader */
241        lwz     r3,bss_length-base_addr(r1)       /* bss length */
242        rlwinm. r3,r3,30,0x3FFFFFFF     /* form length/4 */
243        beqlr                           /* no bss */
244        mtctr   r3                      /* set ctr reg */
245        xor     r6,r6,r6                /* r6 = 0 */
246clear_bss:
247        stswi   r6,r2,0x4               /* store r6 */
248        addi    r2,r2,0x4               /* update r2 */
249        bdnz    clear_bss               /* decrement counter and loop */
250        blr                             /* return */
251.L_text_e:
252
253#if PPC_ABI == PPC_ABI_POWEROPEN
254        DESCRIPTOR (startup)
255#endif
256
257        .comm   environ,4,4
Note: See TracBrowser for help on using the repository browser.