| [444] | 1 | /*
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| 2 | Copyright (c) 2013 Andes Technology Corporation.
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| 3 | All rights reserved.
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| 4 |
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| 5 | Redistribution and use in source and binary forms, with or without
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| 6 | modification, are permitted provided that the following conditions are met:
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| 7 |
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| 8 | Redistributions of source code must retain the above copyright
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| 9 | notice, this list of conditions and the following disclaimer.
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| 10 |
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| 11 | Redistributions in binary form must reproduce the above copyright
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| 12 | notice, this list of conditions and the following disclaimer in the
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| 13 | documentation and/or other materials provided with the distribution.
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| 14 |
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| 15 | The name of the company may not be used to endorse or promote
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| 16 | products derived from this software without specific prior written
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| 17 | permission.
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| 18 |
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| 19 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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| 20 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 21 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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| 22 | DISCLAIMED. IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY
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| 23 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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| 24 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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| 25 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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| 26 | ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 27 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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| 28 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 29 | */
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| 30 | #include "../syscall.h"
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| 31 | #include "syscall_extra.h"
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| 32 |
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| 33 | .extern _impure_ptr /* The first element is _errno. */
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| 34 | .extern _end
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| 35 | .global _sbrk
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| 36 | .type _sbrk, @function
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| 37 |
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| 38 | .text
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| 39 | .align 2
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| 40 | _sbrk:
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| 41 | /* Get the value stored in heap_end (Top of Heap). If the value is zero,
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| 42 | initialize it with the ending of bss section and leave a 1024-byte
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| 43 | room to do low memory action. */
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| 44 | l.w $r1, heap_end
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| 45 | bnez $r1, .L0
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| 46 | /* Note: leave 1024 byte to do low memory action. */
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| 47 | la $r1, _end + 1024
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| 48 | s.w $r1, heap_end
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| 49 |
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| 50 | .L0:
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| 51 | /* Try to increments heap_end by $r0 bytes. Check if collision happens ?
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| 52 | If collision happens, -1 is returned and errno is set to ENOMEM.
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| 53 | Otherwise, save new value to heap_end and return the previous
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| 54 | heap_end. */
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| 55 |
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| 56 | /* Make sure new heap_end is aligned on 8-byte boundary. */
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| 57 | addi $r0, $r0, 7
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| 58 | srli $r0, $r0, 3
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| 59 | slli $r0, $r0, 3
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| 60 |
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| 61 | add $r0, $r1, $r0 /* Set $r0 as new heap_end. */
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| 62 | slt $r2, $sp, $r0 /* Set $r2 if $sp is lower than heap_end. */
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| 63 | bnez $r2, .Lerror /* Branch if collision happens. */
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| 64 |
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| 65 | s.w $r0, heap_end /* Save new value to heap_end. */
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| 66 | move $r0, $r1 /* Return the previous heap_end. */
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| 67 | ret
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| 68 |
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| 69 | .Lerror:
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| 70 | movi $r0, 12
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| 71 | l.w $r15, _impure_ptr
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| 72 | swi $r0, [$r15] /* Set errno. */
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| 73 | movi $r0, -1 /* Reture value is -1. */
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| 74 | ret
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| 75 |
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| 76 | .size _sbrk, .-_sbrk
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| 77 | .section .bss
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| 78 | .align 2
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| 79 | heap_end:
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| 80 | .word 0
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