Annotation of sys/arch/sparc/stand/common/srt0.S, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: srt0.S,v 1.2 2002/08/11 12:20:43 art Exp $ */
! 2: /* $NetBSD: srt0.S,v 1.5.4.2 1996/07/17 01:51:46 jtc Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1994 Paul Kranenburg
! 6: * All rights reserved.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. All advertising materials mentioning features or use of this software
! 17: * must display the following acknowledgement:
! 18: * This product includes software developed by Paul Kranenburg.
! 19: * 4. The name of the author may not be used to endorse or promote products
! 20: * derived from this software without specific prior written permission.
! 21: *
! 22: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 23: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! 24: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! 25: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
! 26: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
! 27: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
! 28: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
! 29: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! 30: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
! 31: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! 32: */
! 33:
! 34: #include <machine/param.h>
! 35: #include <machine/psl.h>
! 36: #include <machine/asm.h>
! 37:
! 38: #define CCFSZ 96
! 39:
! 40: .file "str0.s"
! 41:
! 42: .data
! 43: .global _C_LABEL(cputyp), _C_LABEL(nbpg), _C_LABEL(pgofset)
! 44: .global _C_LABEL(pgshift)
! 45: _C_LABEL(cputyp):
! 46: .word 1
! 47: _C_LABEL(nbpg):
! 48: .word 1
! 49: _C_LABEL(pgofset):
! 50: .word 1
! 51: _C_LABEL(pgshift):
! 52: .word 1
! 53:
! 54: .text
! 55: .globl start
! 56:
! 57: start:
! 58: /*
! 59: * Set up a stack.
! 60: */
! 61: set start, %o1
! 62: save %o1, -CCFSZ, %sp
! 63:
! 64: /*
! 65: * Relocate.
! 66: */
! 67: 1: call 2f
! 68: nop
! 69: 2: add %o7, (start-1b), %l0
! 70: set start, %l1
! 71: set _C_LABEL(end), %o0
! 72: sub %o0, %l1, %l2 ! length
! 73: 3: ld [%l0], %o0
! 74: add %l0, 4, %l0
! 75: st %o0, [%l1]
! 76: subcc %l2, 4, %l2
! 77: bg 3b
! 78: add %l1, 4, %l1
! 79:
! 80: set 4f, %g1
! 81: jmp %g1
! 82: nop
! 83:
! 84: 4:
! 85: #ifdef notyet
! 86: /*
! 87: * Enable traps
! 88: */
! 89: wr %g0, 0, %wim ! make sure we can set psr
! 90: nop; nop; nop
! 91: wr %g0, PSR_S|PSR_PS|PSR_PIL, %psr ! set initial psr
! 92: nop; nop; nop
! 93: wr %g0, 2, %wim ! set initial %wim (w1 invalid)
! 94:
! 95: rd %psr, %l0
! 96: wr %l0, PSR_ET, %psr
! 97: nop; nop; nop
! 98: #endif
! 99:
! 100: /*
! 101: * Clear BSS
! 102: */
! 103: set _C_LABEL(edata), %o0 ! bzero(edata, end - edata)
! 104: set _C_LABEL(end), %o1
! 105: call _C_LABEL(bzero)
! 106: sub %o1, %o0, %o1
! 107:
! 108: /*
! 109: * Enable interrupts, but only above level 11. This enables "L1-A",
! 110: * but avoids spurious interrupt bites from most other devices.
! 111: */
! 112: rd %psr, %o0
! 113: andn %o0, PSR_PIL, %o0
! 114: wr %o0, 0xb00, %psr ! (11 << 8)
! 115: nop; nop; nop
! 116:
! 117: /*
! 118: * Set CPU type that we are running on.
! 119: */
! 120: sethi %hi(_C_LABEL(cputyp)), %o0
! 121: set 0x4000, %g7
! 122: cmp %i0, %g7
! 123: beq 5f
! 124: nop
! 125:
! 126: /*
! 127: * Save address of PROM vector (passed in %i0).
! 128: */
! 129: sethi %hi(_C_LABEL(promvec)), %o1
! 130: st %i0, [%o1 + %lo(_C_LABEL(promvec))]
! 131:
! 132: mov CPU_SUN4C, %g4
! 133: mov SUN4CM_PGSHIFT, %g5
! 134: b,a 6f
! 135:
! 136: 5:
! 137: mov CPU_SUN4, %g4
! 138: mov SUN4_PGSHIFT, %g5
! 139:
! 140: 6:
! 141: st %g4, [%o0 + %lo(_C_LABEL(cputyp))]
! 142: sethi %hi(_C_LABEL(pgshift)), %o0 ! pgshift = log2(nbpg)
! 143: st %g5, [%o0 + %lo(_C_LABEL(pgshift))]
! 144:
! 145: mov 1, %o0 ! nbpg = 1 << pgshift
! 146: sll %o0, %g5, %g5
! 147: sethi %hi(_C_LABEL(nbpg)), %o0 ! nbpg = bytes in a page
! 148: st %g5, [%o0 + %lo(_C_LABEL(nbpg))]
! 149:
! 150: sub %g5, 1, %g5
! 151: sethi %hi(_C_LABEL(pgofset)), %o0 ! page offset = bytes in a page - 1
! 152: st %g5, [%o0 + %lo(_C_LABEL(pgofset))]
! 153:
! 154: call _C_LABEL(main)
! 155: mov %i0, %o0
! 156:
! 157: ret
! 158: restore
! 159:
! 160:
! 161: #ifdef TIGHT
! 162:
! 163: /*
! 164: * XXX - Space saving .div & .rem routines (small & non-negative numbres only)
! 165: */
! 166: .align 4
! 167: .global .div, .udiv
! 168: ! int n = 0; while (a >= b) { a -= b; n++; }; return n;
! 169: .div:
! 170: .udiv:
! 171: cmp %o0, %o1
! 172: bl 2f
! 173: mov 0, %o5
! 174: 1:
! 175: sub %o0, %o1, %o0
! 176: cmp %o0, %o1
! 177: bge 1b
! 178: add %o5, 1, %o5
! 179: 2:
! 180: retl
! 181: mov %o5, %o0
! 182:
! 183: .align 4
! 184: .global .rem, .urem
! 185: ! while (a>=b) a -= b; return a;
! 186: .rem:
! 187: .urem:
! 188: cmp %o0, %o1
! 189: bl 2f
! 190: nop
! 191: sub %o0, %o1, %o0
! 192: 1:
! 193: cmp %o0, %o1
! 194: bge,a 1b
! 195: sub %o0, %o1, %o0
! 196: 2:
! 197: retl
! 198: nop
! 199:
! 200: #endif /* TIGHT */
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