16f4fc3263
* module/mescc/M1.scm (riscv:i-format, riscv:j-format, riscv:u-format): New procedures for RISC-V instruction formats. (info->M1): Use them to switch from !0xAB to M1 weird strings 'AB'. * module/mescc/riscv64/as.scm, lib/linux/riscv64-mes-m2/_exit.c ib/linux/riscv64-mes-m2/_write.c,. lib/linux/riscv64-mes-m2/crt1.M1,. lib/linux/riscv64-mes-m2/syscall.c,. lib/linux/riscv64-mes-mescc/_exit.c,. lib/linux/riscv64-mes-mescc/_write.c,. lib/linux/riscv64-mes-mescc/crt1.c,. lib/linux/riscv64-mes-mescc/syscall-internal.c,. lib/linux/riscv64-mes-mescc/syscall.c,. lib/m2/riscv64/riscv64_defs.M1,. lib/riscv64-mes-mescc/setjmp.c,. lib/riscv64-mes/riscv64.M1: Switch to riscv64 word-based macros. * lib/linux/open.c (open)[!SYS_open]: Add support using openat syscall. * include/linux/riscv64/syscall.h (MAKESTRING, MAKESTRING2, RISCV_SYSCALL): New macros.
61 lines
2 KiB
C
61 lines
2 KiB
C
/* -*-comment-start: "//";comment-end:""-*-
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* GNU Mes --- Maxwell Equations of Software
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* Copyright © 2018,2023 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
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* Copyright © 2021 W. J. van der Laan <laanwj@protonmail.com>
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* Copyright © 2023 Andrius Štikonas <andrius@stikonas.eu>
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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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*/
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#include "mes/lib-mini.h"
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#include "linux/riscv64/syscall.h"
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int main (int argc, char *argv[], char *envp[]);
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/* mesc will generate the following preamble:
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push ra
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push fp
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*/
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int
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_start ()
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{
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asm ("rd_t1 rs1_fp mv");
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asm ("rd_t1 rs1_t1 !0x18 addi"); // 0x10 to skip over pushed fp+ra, 0x8 to skip over argc
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asm ("rd_t5 rs1_fp !0x10 addi"); // 0x10 to skip over pushed fp+ra
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asm ("rd_t0 rs1_t5 ld");
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asm ("rd_t0 rs1_t0 !1 addi");
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asm ("rd_t5 !3 addi"); // skip over all arguments and the final NULL
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asm ("rd_t0 rs1_t0 rs2_t5 sll");
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asm ("rd_t0 rs1_t0 rs2_t1 add");
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asm ("rd_sp rs1_sp !-8 addi"); // push envp onto stack
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asm ("rs1_sp rs2_t0 sd");
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asm ("rd_sp rs1_sp !-8 addi"); // push argv onto stack
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asm ("rs1_sp rs2_t1 sd");
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asm ("rd_t5 rs1_fp !0x10 addi"); // 0x10 to skip over pushed fp+ra
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asm ("rd_t0 rs1_t5 ld");
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asm ("rd_sp rs1_sp !-8 addi"); // push argc onto stack
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asm ("rs1_sp rs2_t0 sd");
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__init_io ();
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main ();
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asm ("rd_a0 rs1_t0 mv");
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asm (RISCV_SYSCALL(SYS_exit));
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asm ("ecall");
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asm ("ebreak");
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}
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