source: trunk/libs/newlib/src/libgloss/frv/crt0.S @ 687

Last change on this file since 687 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 7.5 KB
RevLine 
[444]1/* crt0.S -- startup file for frv.
2 *
3 * Copyright (c) 2002, 2003 Red Hat, Inc
4 *
5 * The authors hereby grant permission to use, copy, modify, distribute,
6 * and license this software and its documentation for any purpose, provided
7 * that existing copyright notices are retained in all copies and that this
8 * notice is included verbatim in any distributions. No written agreement,
9 * license, or royalty fee is required for any of the authorized uses.
10 * Modifications to this software may be copyrighted by their authors
11 * and need not follow the licensing terms described here, provided that
12 * the new terms are clearly indicated on the first page of each file where
13 * they apply.
14 */
15
16#include <frv-asm.h>
17
18        /* statically store .Lcall's address so we can see if we are running
19           at the location we were linked for or a different location.  */
20        .data
21        .type   EXT(__start_cmp),@object
22        .size   EXT(__start_cmp),4
23        .p2align 2
24EXT(__start_cmp):
25        .picptr  .Lcall
26       
27        .globl  __start
28        .weak   _start
29        .text
30        .type   __start,@function
31__start:
32_start:
33        call    .Lcall                          /* set up _gp in a pic-friendly manor */
34.Lcall: movsg   lr, gr4
35        P(sethi) #gprelhi(.Lcall), gr5
36        setlo    #gprello(.Lcall), gr5
37        P(sub)   gr4, gr5, gr16
38
39#if ! __FRV_FDPIC__
40        sethi    #gprelhi(EXT(_stack)), sp      /* load up stack pointer */
41        P(setlo) #gprello(EXT(_stack)), sp
42        setlos   #0, fp                         /* zero fp to allow unwinders to stop */
43        P(add)   sp, gr16, sp
44
45#define FDPIC(...)
46#else
47#define FDPIC(...) __VA_ARGS__
48       
49        /* The assembler will rightfully claim that
50        #hi/lo(__stacksize) are unsafe for PIC, but since __stacksize
51        is absolute, and we don't want it to be relocated, we should
52        be fine.  */
53
54        sethi   #gprelhi(EXT(__end)), gr6
55        P(sethi) #hi(EXT(__stacksize+7)), gr5
56        setlo   #gprello(EXT(__end)), gr6
57        P(setlo) #lo(EXT(__stacksize+7)), gr5
58        add     gr6, gr16, gr6
59        add     gr6, gr5, gr5
60        andi    gr5, -8, sp
61
62        /* Using GPREL to compute _GLOBAL_OFFSET_TABLE_'s will force
63        the entire program to relocate as a unit, which is fine for
64        frv-elf.  */
65       
66        P(sethi) #gprelhi(EXT(_GLOBAL_OFFSET_TABLE_)), gr15
67        setlo    #gprello(EXT(_GLOBAL_OFFSET_TABLE_)), gr15
68        /* We compute the value in a call-saved register (that happens
69        to be the PIC register in the EABI, and copy it to gr15 before
70        every call.  */
71        add      gr15, gr16, gr17
72#endif
73
74        sethi    #gprelhi(EXT(__start_cmp)), gr5
75        setlo    #gprello(EXT(__start_cmp)), gr5
76        ld       @(gr5,gr16), gr6
77        subcc   gr4, gr6, gr8, icc0
78        beq     icc0, 0, .Lfixed
79
80        P(st)   gr4, @(gr5, gr16)       /* update so if we restart no need to fixup */
81        setlos  4, gr11
82
83#if ! __FRV_FDPIC__
84
85                                        /* fixup the .ctors list */
86        sethi    #gprelhi(EXT(__CTOR_LIST__)), gr9
87        P(sethi) #gprelhi(EXT(__CTOR_END__)), gr10
88        setlo    #gprello(EXT(__CTOR_LIST__)), gr9
89        P(setlo) #gprello(EXT(__CTOR_END__)), gr10
90        add      gr9, gr16, gr9
91        P(add)   gr10, gr16, gr10
92        addi     gr9, 4, gr9
93        P(subi)  gr10, 4, gr10
94        call     EXT(__frv_fixptrs)
95
96                                        /* fixup the .dtors list */
97        P(sethi) #gprelhi(EXT(__DTOR_LIST__)), gr9
98        sethi    #gprelhi(EXT(__DTOR_END__)), gr10
99        P(setlo) #gprello(EXT(__DTOR_LIST__)), gr9
100        setlo    #gprello(EXT(__DTOR_END__)), gr10
101        P(add)   gr9, gr16, gr9
102        add      gr10, gr16, gr10
103        P(addi)  gr9, 4, gr9
104        subi     gr10, 4, gr10
105        call     EXT(__frv_fixptrs)
106#endif /* ! __FRV_FDPIC__ */
107
108                                        /* fixup the user .rofixup list */
109        P(sethi) #gprelhi(EXT(__ROFIXUP_LIST__)), gr9
110        sethi    #gprelhi(EXT(__ROFIXUP_END__)), gr10
111        P(setlo) #gprello(EXT(__ROFIXUP_LIST__)), gr9
112        setlo    #gprello(EXT(__ROFIXUP_END__)), gr10
113        P(add)   gr9, gr16, gr9
114        add      gr10, gr16, gr10
115        FDPIC(mov gr17, gr15)
116        call     EXT(__frv_fix_usrptrs)
117
118.Lfixed:
119
120/* HSR flags */
121#define HSR_ICE  0x80000000             /* Instruction cache enable */
122#define HSR_DCE  0x40000000             /* Data cache enable */
123#define HSR_CBM  0x08000000             /* Cache copy back mode */
124#define HSR_EIMM 0x04000000             /* Enable Instruction MMU */
125#define HSR_EDMM 0x02000000             /* Enable Data MMU */
126#define HSR_EMEM 0x00800000             /* Enable MMU miss exception mask */
127#define HSR_RME  0x00400000             /* Ram mode enable */
128#define HSR_SA   0x00001000             /* Start address */
129#define HSR_FRN  0x00000800             /* Number of FPRs */
130#define HSR_GRN  0x00000400             /* Number of GPRs */
131#define HSR_FRHE 0x00000200             /* FR Higher Enable */
132#define HSR_FRLE 0x00000100             /* FR Lower Enable */
133#define HSR_GRHE 0x00000080             /* GR Higher Enable */
134#define HSR_GRLE 0x00000040             /* GR Lower Enable */
135
136#ifndef HSR_CLEAR
137#define HSR_CLEAR 0
138#endif
139
140#ifndef HSR_SET
141#ifndef FRV_NO_CACHE
142#define HSR_SET (HSR_ICE|HSR_DCE|HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE)
143#else
144#define HSR_SET (HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE)
145#endif
146#endif
147
148/* PSR flags */
149#define PSR_ICE  0x00010000             /* In circuit emulation mode */
150#define PSR_NEM  0x00004000             /* Non-exception mode */
151#define PSR_CM   0x00002000             /* Conditional mode */
152#define PSR_BE   0x00001000             /* Big endian mode */
153#define PSR_EF   0x00000100             /* Enable floating point */
154#define PSR_EM   0x00000080             /* Enable media instructions */
155#define PSR_S    0x00000004             /* Enable supervisor mode */
156#define PSR_PS   0x00000002             /* Previous supervisor mode */
157#define PSR_ET   0x00000001             /* Enable interrupts */
158
159#ifndef PSR_CLEAR
160#if __FRV_FPR__
161#define PSR_CLEAR 0
162#else
163#define PSR_CLEAR (PSR_EF|PSR_EM)
164#endif
165#endif
166
167#ifndef PSR_SET
168#if __FRV_FPR__
169#define PSR_SET (PSR_NEM|PSR_CM|PSR_EF|PSR_EM)
170#else
171#define PSR_SET (PSR_NEM|PSR_CM)
172#endif
173#endif
174
175        /* Enable floating point */
176        movsg     hsr0, gr4
177        P(sethi)  #hi(HSR_SET), gr5
178        setlo     #lo(HSR_SET), gr5
179        P(sethi)  #hi(~HSR_CLEAR), gr6
180        setlo     #lo(~HSR_CLEAR), gr6
181        or        gr4, gr5, gr4
182        and       gr4, gr6, gr4
183        movgs     gr4, hsr0
184
185        movsg     psr, gr4
186        P(sethi)  #hi(PSR_SET), gr5
187        setlo     #lo(PSR_SET), gr5
188        P(sethi)  #hi(~PSR_CLEAR), gr6
189        setlo     #lo(~PSR_CLEAR), gr6
190        or        gr4, gr5, gr4
191        and       gr4, gr6, gr4
192        movgs     gr4, psr
193
194        /* zero the bss area */
195        P(sethi)  #gprelhi(__bss_start), gr8
196        sethi     #gprelhi(__end), gr4
197        P(setlo)  #gprello(__bss_start), gr8
198        setlo     #gprello(__end), gr4
199        P(add)    gr8, gr16, gr8
200        add       gr4, gr16, gr4
201        P(setlos) #0, gr9
202        sub       gr4, gr8, gr10
203        FDPIC(mov gr17, gr15)
204        call      EXT(memset)
205
206        P(setlos) #0, gr8               /* zero argc, argv, envp */
207        setlos    #0, gr9
208        P(setlos) #0, gr10
209
210        FDPIC(mov gr17, gr15)
211        call      EXT(main)
212        FDPIC(mov gr17, gr15)
213        call      EXT(exit)
214.Lend:
215        .size   __start,(.Lend-__start)
216
217#if ! __FRV_FDPIC__
218        /* Routine to adjust pointers
219           gr8  = difference to adjust by
220           gr9  = starting address
221           gr10 = ending address + 4
222           gr11 = amount to add to the pointer each iteration.  */
223        .globl  EXT(__frv_fixptrs)
224        .type   EXT(__frv_fixptrs),@function
225EXT(__frv_fixptrs):
226        P(sub)  gr9, gr11, gr9
227        sub     gr10, gr11, gr10
228.Lloop2:
229        cmp     gr10, gr9, icc0
230        bls     icc0, 0, .Lret2
231
232        ldu     @(gr9,gr11), gr5
233        add     gr8, gr5, gr5
234        P(st)   gr5, @(gr9,gr0)
235        bra     .Lloop2
236
237.Lret2: ret
238.Lend2:
239        .size   EXT(__frv_fixptrs),.Lend2-EXT(__frv_fixptrs)
240#endif /* ! __FRV_FDPIC__ */
241
242        /* Routine to adjust statically initialized pointers
243           Note since these are pointers to pointers, they
244           need to be adjusted themsevles.
245
246           gr8  = difference to adjust by
247           gr9  = starting address
248           gr10 = ending address + 4
249           gr11 = amount to add to the pointer each iteration.  */
250        .globl  EXT(__frv_fix_usrptrs)
251        .type   EXT(__frv_fix_usrptrs),@function
252EXT(__frv_fix_usrptrs):
253        P(sub)  gr9, gr11, gr9
254        sub     gr10, gr11, gr10
255.Lloop3:
256        cmp     gr10, gr9, icc0
257        bls     icc0, 0, .Lret3
258
259        ldu     @(gr9,gr11), gr5
260        ld      @(gr5, gr8), gr6
261        cmp     gr6, gr0, icc0          /* skip pointers initialized to 0 */
262        beq     icc0, 0, .Lloop3
263
264        add     gr8, gr6, gr6
265        P(st)   gr6, @(gr5,gr8)
266        bra     .Lloop3
267
268.Lret3: ret
269.Lend3:
270        .size   EXT(__frv_fix_usrptrs),.Lend3-EXT(__frv_fix_usrptrs)
271
272        .section .data
273        .global __dso_handle
274        .weak __dso_handle
275__dso_handle:
276        .long   0
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