diff options
Diffstat (limited to 'exec/loader-mips64el.s')
| -rw-r--r-- | exec/loader-mips64el.s | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/exec/loader-mips64el.s b/exec/loader-mips64el.s new file mode 100644 index 00000000000..0ff140f9f31 --- /dev/null +++ b/exec/loader-mips64el.s @@ -0,0 +1,234 @@ +# Copyright (C) 2023-2024 Free Software Foundation, Inc. +# +# This file is part of GNU Emacs. +# +# GNU Emacs is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published +# by the Free Software Foundation, either version 3 of the License, +# or (at your option) any later version. +# +# GNU Emacs is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. + +include(`config-mips.m4') + + .set noreorder # delay slots managed by hand + .set noat # no assembler macros + .section .text + .global __start +__start: +dnl li $v0, 5034 # SYS_nanosleep +dnl dla $a0, .timespec # rqtp +dnl li $a1, 0 # rmtp +dnl syscall # syscall + ld $s2, ($sp) # original stack pointer + DADDI3( $s0, $sp, 16) # start of load area + DADDI2( $sp, -16) # primary fd, secondary fd + li $t0, -1 # secondary fd + sd $t0, 8($sp) # initialize secondary fd +.next_action: + ld $s1, ($s0) # action number + andi $t0, $s1, 15 # t0 = action number & 15 + beqz $t0, .open_file # open file? + nop # delay slot + DADDI2( $t0, -3) # t0 -= 3 + beqz $t0, .rest_of_exec # jump to code + nop # delay slot + li $t1, 1 + beq $t0, $t1, .do_mmap_anon # anonymous mmap? + nop # delay slot +.do_mmap: + ld $t0, 8($s0) # vm address + ld $t1, 16($s0) # file_offset + ld $t2, 24($s0) # protection + ld $t3, 32($s0) # length + ld $v0, 40($s0) # flags + ld $v1, ($sp) # primary fd + andi $s3, $s1, 16 # s1 & 16? + beqz $s3, .do_mmap_1 # secondary fd? + nop # delay slot + ld $v1, 8($sp) # secondary fd +.do_mmap_1: + move $a0, $t0 # syscall arg + move $a1, $t3 # syscall arg + move $a2, $t2 # syscall arg + move $a3, $v0 # syscall arg + move $a4, $v1 # syscall arg + move $a5, $t1 # syscall arg + li $v0, 5009 # SYS_mmap + syscall # syscall + bne $a3, $zero, .perror # perror? + nop # delay slot + ld $t1, 48($s0) # clear + dadd $t0, $a0, $a1 # t0 = end of mapping + dsub $t1, $t0, $t1 # t1 = t0 - clear +.align: + beq $t0, $t1, .continue # already finished + nop # delay slot + andi $t2, $t1, 7 # t1 & 7? + bnez $t2, .filld # start filling longs + nop # delay slot +.filld: + dsub $t2, $t0, $t1 # t2 = t0 - t1 + sltiu $t2, $t2, 64 # t2 < 64? + bne $t2, $zero, .fillb # fill bytes + nop # delay slot + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + sd $zero, ($t1) # zero doubleword + DADDI2( $t1, 8) # next doubleword + j .filld # fill either doubleword or byte + nop # delay slot +.fillb: + beq $t0, $t1, .continue # already finished? + nop # delay slot + sb $zero, ($t1) # clear byte + DADDI2( $t1, 1) # t1++ +.continue: + DADDI2( $s0, 56) # s0 = next action + j .next_action # next action + nop # delay slot +.do_mmap_anon: + ld $t0, 8($s0) # vm address + ld $t1, 16($s0) # file_offset + ld $t2, 24($s0) # protection + ld $t3, 32($s0) # length + ld $v0, 40($s0) # flags + li $v1, -1 # fd + j .do_mmap_1 # do mmap + nop # branch delay slot +.open_file: + li $v0, 5002 # SYS_open + DADDI3( $a0, $s0, 8) # start of name + move $a1, $zero # flags = O_RDONLY + move $a2, $zero # mode = 0 + syscall # syscall + bne $a3, $zero, .perror # perror + nop # delay slot + DADDI2( $s0, 8) # start of string + move $t3, $s0 # t3 = s0 +.nextc: + lb $t0, ($s0) # load byte + DADDI2( $s0, 1) # s0++ + li $t1, 47 # directory separator `/' + bne $t0, $t1, .nextc1 # is separator char? + nop # delay slot + move $t3, $s0 # t3 = char past separator +.nextc1: + bnez $t0, .nextc # next character? + nop # delay slot + DADDI2( $s0, 7) # adjust for round + li $t2, -8 # t2 = -8 + and $s0, $s0, $t2 # mask for round + andi $t0, $s1, 16 # t1 = s1 & 16 + move $t1, $sp # address of primary fd + beqz $t0, .primary # primary fd? + nop # delay slot + DADDI2( $t1, 8) # address of secondary fd + sd $v0, ($t1) # store fd + j .next_action # next action + nop # delay slot +.primary: + sd $v0, ($t1) # store fd + li $v0, 5153 # SYS_prctl + li $a0, 15 # PR_SET_NAME + move $a1, $t3 # char past separator + move $a2, $zero # a2 + move $a3, $zero # a3 + move $a4, $zero # a4 + move $a5, $zero # a5 + syscall # syscall + j .next_action # next action + nop # delay slot +.perror: + move $a0, $v0 # errno + li $v0, 5058 # SYS_exit + syscall # syscall +.rest_of_exec: + move $s1, $s2 # original SP + ld $t0, ($s1) # argc + dsll $t0, $t0, 3 # argc *= 8 + DADDI2( $t0, 16) # argc += 16 + dadd $s1, $s1, $t0 # s1 = start of envp +.skipenv: + ld $t0, ($s1) # t0 = *s1 + DADDI2( $s1, 8) # s1++ + bne $t0, $zero, .skipenv # skip again + nop # delay slot + dla $t3, .auxvtab # address of auxv table +.one_auxv: + ld $t0, ($s1) # t0 = auxv type + li $t1, 10 # t1 = 10 + beqz $t0, .finish # is AT_IGNORE? + nop # delay slot + sltu $t1, $t0, $t1 # t1 = t0 < num offsets + beqz $t1, .next # next auxv + nop # delay slot + dsll $t1, $t0, 2 # t1 = t0 * 4 + dadd $t1, $t3, $t1 # t1 = .auxvtab + t1 + lw $t2, ($t1) # t2 = *t1 + beqz $t2, .next # skip auxv + nop # delay slot + dadd $t2, $s0, $t2 # t2 = s0 + t2 + ld $t2, ($t2) # t2 = *t2 + sd $t2, 8($s1) # set auxv value +.next: + DADDI2( $s1, 16) # next auxv + j .one_auxv # next auxv + nop # delay slot +.finish: + ld $t0, 8($sp) # secondary fd + li $t1, -1 # t1 = -1 + ld $s1, ($sp) # s1 = primary fd + li $v0, 5003 # SYS_close + beq $t0, $t2, .finish1 # secondary fd set? + nop # delay slot + move $a0, $t0 # secondary fd + syscall # syscall + li $v0, 5003 # SYS_close +.finish1: + move $a0, $s1 # primary fd + syscall # syscall +.jump: + move $v0, $zero # rtld_fini + ld $t0, 8($s0) # entry + move $sp, $s2 # restore stack pointer, delay slot + jr $t0 # enter + nop # delay slot + +.auxvtab: + .long 0 # 0 + .long 0 # 1 + .long 0 # 2 + .long 40 # 3 AT_PHDR + .long 24 # 4 AT_PHENT + .long 32 # 5 AT_PHNUM + .long 0 # 6 + .long 48 # 7 AT_BASE + .long 0 # 8 + .long 16 # 9 AT_ENTRY + +.timespec: + .quad 10 + .quad 10 + +# Local Variables: +# asm-comment-char: ?# +# End: |