74 lines
1.8 KiB
Plaintext
74 lines
1.8 KiB
Plaintext
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### GNU Mes --- Maxwell Equations of Software
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### Copyright (C) 2016 Jeremiah Orians
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### Copyright © 2022 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
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###
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### This file is part of GNU Mes.
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###
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### GNU Mes is free software; you can redistribute it and/or modify it
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### under the terms of the GNU General Public License as published by
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### the Free Software Foundation; either version 3 of the License, or (at
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### your option) any later version.
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###
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### GNU Mes is distributed in the hope that it will be useful, but
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### WITHOUT ANY WARRANTY; without even the implied warranty of
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### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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### GNU General Public License for more details.
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###
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### You should have received a copy of the GNU General Public License
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### along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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:_start
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; sp has to be 16 byte aligned but we only want to deal with 8 byte registers,
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; so use a normal register as sp
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INIT_SP ; mov x18, sp
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LDR_X0_[SP]
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ADD_X1_SP_8
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; M2-Planet also has a frame pointer, x17
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SET_BP_FROM_SP ; mov x17, x18
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; Separate out envp, get our args for main
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PUSH_X0 ; argc
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PUSH_X1 ; argv (yes, that's above the top of the stack)
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SET_X1_TO_2 ; One word for argc, one word for a null pointer
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ADD_X0_X1_X0
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SET_X1_TO_8
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MUL_X0_X1_X0
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ADD_X0_BP_X0
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PUSH_X0 ; envp
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; Store envp to environ global
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LOAD_W1_AHEAD
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SKIP_32_DATA
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&GLOBAL_environ
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STR_X0_[X1]
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; Set stdin, stdout, and stderr
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SET_X0_TO_0
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LOAD_W1_AHEAD
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SKIP_32_DATA
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&GLOBAL___stdin
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STR_X0_[X1]
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SET_X0_TO_1
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LOAD_W1_AHEAD
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SKIP_32_DATA
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&GLOBAL___stdout
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STR_X0_[X1]
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SET_X0_TO_2
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SKIP_32_DATA
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&GLOBAL___stderr
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STR_X0_[X1]
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; Call our main function
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LOAD_W16_AHEAD
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SKIP_32_DATA
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&FUNCTION_main
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BLR_X16
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; Exit
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; Return from main is already in x0
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SET_X8_TO_SYS_EXIT
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SYSCALL
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