| /* |
| * C startup code for the Fujitsu SPARClite demo board |
| * |
| * Copyright (c) 1995, 1996 Cygnus Support |
| * |
| * The authors hereby grant permission to use, copy, modify, distribute, |
| * and license this software and its documentation for any purpose, provided |
| * that existing copyright notices are retained in all copies and that this |
| * notice is included verbatim in any distributions. No written agreement, |
| * license, or royalty fee is required for any of the authorized uses. |
| * Modifications to this software may be copyrighted by their authors |
| * and need not follow the licensing terms described here, provided that |
| * the new terms are clearly indicated on the first page of each file where |
| * they apply. |
| */ |
| #include "asm.h" |
| |
| .data |
| .align 8 |
| .ascii "DaTa" ! this is the first address in the data section |
| .long SYM(sdata) |
| SYM(environ): |
| .long 0 |
| |
| .text |
| .align 8 |
| |
| .globl SYM(_start) |
| SYM(_start): |
| .globl SYM(start) |
| SYM(start): |
| /* see if the stack is already setup. if not, then default |
| * to using the value of %sp as set by the ROM monitor |
| */ |
| sethi %hi(__stack), %g1 |
| or %g1,%lo(__stack),%g1 |
| cmp %g0,%g1 |
| be 1f |
| mov %g1, %sp ! set the stack pointer |
| mov %sp, %fp |
| 1: |
| |
| /* zero the bss section */ |
| sethi %hi(__bss_start),%g2 |
| or %g2,%lo(__bss_start),%g2 ! start of bss |
| sethi %hi(_end),%g3 |
| or %g3,%lo(_end),%g3 ! end of bss |
| mov %g0,%g1 ! so std has two zeros |
| zerobss: |
| std %g0,[%g2] |
| add %g2,8,%g2 |
| cmp %g2,%g3 |
| bleu,a zerobss |
| nop |
| |
| /* |
| * copy prom & trap vectors to sram. |
| */ |
| set 0x30000000, %l0 |
| set 0xfff8, %l1 |
| tst %l1 ! Set condition codes |
| |
| copyloop: |
| ldd [%l1], %l2 |
| std %l2, [%l0 + %l1] |
| bg copyloop |
| deccc 8, %l1 |
| |
| set 0x30000000, %l0 ! Base of new trap vector |
| mov %l0, %tbr ! Install the new tbr |
| |
| set SYM(win_ovf_trap), %l1 ! Setup window overflow trap |
| ldd [%l1], %l2 |
| std %l2, [%l0 + 5 * 16] |
| ldd [%l1 + 8], %l2 |
| std %l2, [%l0 + 5 * 16 + 8] |
| |
| set SYM(win_unf_trap), %l1 ! Setup window underflow trap |
| ldd [%l1], %l2 |
| std %l2, [%l0 + 6 * 16] |
| ldd [%l1 + 8], %l2 |
| std %l2, [%l0 + 6 * 16 + 8] |
| |
| /* |
| * Try enabling the FPU by setting EF. If that causes a trap, then we probably |
| * don't have an FPU. |
| */ |
| |
| ldd [%l0 + 2 * 16], %l4 ! Save original trap routine |
| set SYM(no_fpu_trap), %l1 ! Install new one |
| ldd [%l1], %l2 |
| std %l2, [%l0 + 2 * 16] |
| |
| mov %psr, %l0 |
| sethi %hi(0x1000), %l1 |
| bset %l1, %l0 |
| ! mov %l0, %psr |
| |
| std %l4, [2 * 16] ! Restore original trap routine |
| |
| |
| /* |
| * Move the data segment from it's ROM address to RAM where it |
| * belongs. |
| */ |
| |
| relocd: |
| #if 0 /* This code is broken. FIXME */ |
| set (_sdata),%g2 ! %g2 = start of data in aout file |
| set SYM(environ),%g4 ! %g4 = actual data base address |
| set (_edata),%g3 ! %g3 = end of where data should go |
| subcc %g3, %g4, %g5 ! %g5 = length of data |
| |
| subcc %g4, %g2, %g0 ! need to relocate data ? |
| ble init |
| ld [%g4], %g6 |
| subcc %g6, 1, %g0 |
| be init |
| mvdata: |
| subcc %g5, 8, %g5 |
| ldd [%g2 + %g5], %g6 |
| bg mvdata |
| #endif |
| |
| /* |
| * initialize target specific stuff. Only execute these |
| * functions it they exist. |
| */ |
| init: |
| sethi %hi(SYM(hardware_init_hook)), %g1 |
| or %g1,%lo(SYM(hardware_init_hook)),%g1 |
| cmp %g0,%g1 |
| be 1f |
| nop |
| call SYM(hardware_init_hook) |
| nop |
| |
| 1: |
| sethi %hi(SYM(software_init_hook)), %g1 |
| or %g1,%lo(SYM(software_init_hook)),%g1 |
| cmp %g0,%g1 |
| be 2f |
| nop |
| call SYM(software_init_hook) |
| nop |
| 2: |
| call SYM(main) |
| nop |
| |
| /* call exit from the C library so atexit gets called, and the |
| * C++ destructors get run. This calls our exit routine below |
| * when it's done. |
| */ |
| call SYM(exit) |
| nop |
| |
| /* |
| * This should drop control back to the ROM monitor, if there is |
| * one. |
| */ |
| .globl SYM(_exit) |
| SYM(_exit): |
| call 0 |
| nop |
| |
| /* |
| * Trap handlers. |
| */ |
| |
| .align 8 |
| |
| SYM(win_ovf_trap): |
| sethi %hi(SYM(win_ovf)), %l3 |
| jmpl %lo(SYM(win_ovf))+%l3, %g0 |
| mov %wim, %l0 |
| nop |
| |
| SYM(win_unf_trap): |
| sethi %hi(SYM(win_unf)), %l3 |
| jmpl %lo(SYM(win_unf))+%l3, %g0 |
| mov %wim, %l0 |
| nop |
| |
| SYM(no_fpu_trap): ! Come here when no fpu exists. |
| jmpl %l2, %g0 ! This just skips the |
| rett %l2+4 ! offending instruction. |