usr/source/s4/read.s

/ C library -- read

/ nread = read(file, buffer, count);
/
/ nread ==0 means eof; nread == -1 means error

.globl  _read, retrn, cerror

_read:
        mov     r5,-(sp)
        mov     sp,r5
        mov     4(r5),r0
        mov     6(r5),0f
        mov     8(r5),0f+2
        sys     0; 9f
        bec     1f
        jmp     cerror
1:
        jmp     retrn
.data
9:
        sys     read; 0:..; ..