this code was using $10 to save the syscall number, but $10 is not
necessarily preserved by the kernel across syscalls. only mattered for
syscalls that got interrupted by a signal and restarted. as far as i
can tell, $25 is preserved by the kernel across syscalls.
.global __syscall
.type __syscall,@function
__syscall:
.global __syscall
.type __syscall,@function
__syscall:
move $4, $5
move $5, $6
move $6, $7
move $4, $5
move $5, $6
move $6, $7
subu $sp, $sp, 32
sw $8, 16($sp)
sw $9, 20($sp)
subu $sp, $sp, 32
sw $8, 16($sp)
sw $9, 20($sp)
syscall
beq $7, $0, 1f
addu $sp, $sp, 32
syscall
beq $7, $0, 1f
addu $sp, $sp, 32