forked from OctaForge/libostd
92 lines
4.0 KiB
ArmAsm
92 lines
4.0 KiB
ArmAsm
/*
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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*/
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/*******************************************************
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* *
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* ------------------------------------------------- *
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* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | *
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* ------------------------------------------------- *
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* | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c| *
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* ------------------------------------------------- *
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* | fs0 | fs1 | fs2 | fs3 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | *
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* ------------------------------------------------- *
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* | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c| *
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* ------------------------------------------------- *
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* | fs4 | fs5 | fs6 | fs7 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | *
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* ------------------------------------------------- *
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* | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c| *
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* ------------------------------------------------- *
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* | fs8 | fs9 | fs10 | fs11 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | *
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* ------------------------------------------------- *
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* | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c| *
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* ------------------------------------------------- *
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* | s0 | s1 | s2 | s3 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | *
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* ------------------------------------------------- *
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* | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c| *
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* ------------------------------------------------- *
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* | s4 | s5 | s6 | s7 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | *
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* ------------------------------------------------- *
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* | 0xa0| 0xa4| 0xa8| 0xac| 0xb0| 0xb4| 0xb8| 0xbc| *
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* ------------------------------------------------- *
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* | s8 | s9 | s10 | s11 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 48 | 49 | 50 | 51 | | | | | *
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* ------------------------------------------------- *
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* | 0xc0| 0xc4| 0xc8| 0xcc| | | | | *
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* ------------------------------------------------- *
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* | ra | pc | | | *
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* ------------------------------------------------- *
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* *
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*******************************************************/
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.file "make_riscv64_sysv_elf_gas.S"
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.text
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.align 1
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.global ostd_make_fcontext
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.type ostd_make_fcontext, %function
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ostd_make_fcontext:
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# shift address in a0 (allocated stack) to lower 16 byte boundary
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andi a0, a0, ~0xF
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# reserve space for context-data on context-stack
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addi a0, a0, -0xd0
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# third arg of ostd_make_fcontext() == address of context-function
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# store address as a PC to jump in
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sd a2, 0xc8(a0)
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# save address of finish as return-address for context-function
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# will be entered after context-function returns (RA register)
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la a4, finish
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sd a4, 0xc0(a0)
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ret // return pointer to context-data (a0)
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finish:
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# exit code is zero
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li a0, 0
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# exit application
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tail _exit
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.size ostd_make_fcontext,.-ostd_make_fcontext
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# Mark that we don't need executable stack.
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.section .note.GNU-stack,"",%progbits
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