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Length: 2128 (0x850)
Types: TextFile
Notes: UNIX file
Names: »signal.s«
└─⟦f27320a65⟧ Bits:30001972 Commodore 900 hard disk image with partial source code
└─⟦f4b8d8c84⟧ UNIX Filesystem
└─⟦this⟧ »libc/sys/signal.s«
/ / C interface routines for the signal system call. / This is not just a direct call, but must save / and restore user state before and after processing / user signal code. / / int (*(*))() signal(signo, function) int signo; int (*function)(); / int signo; / int (*function)(); NSIG = 16 .globl signal_ signal_: ld r1, rr14(4) / signo cp r1, $NSIG jr ugt, 0f / > NSIG illegal ldl rr2, rr14(6) / check function argument cpl rr2, $1 / is function ? jr ule, 0f / 0 or 1 (SIG_DFL or SIG_IGN) ldl rr2, $sigsave / pointer pushl (rr14), rr2 / changed to sigsave push (rr14), r1 / signo pushl (rr14), rr0 / and junk PC address sys 060 / 48 inc r15, $10 / pop args jr un, 1f / return value 0: sys 060 / 48 1: cp r1, $-1 jr eq, 1f / error return sub r2, r2 / clear high half of rr2 ld r3, rr14(4) / signo add r3, r3 / multiply index by 4 to add r3, r3 / check old signal setting addl rr2, $sigtable-4 / in sig table ldl rr4, (rr2) / Looking at sigtable[signo-1] cpl rr4, $-1 / jr eq, 0f / unknown: yield syscall return ldl rr0, (rr2) / else yield old user function 0: ldl rr4, rr14(6) / Save new user function ldl (rr2), rr4 / in table 1: ret / This routine is called after the system has pushed PC, FCW, and / signal number onto the stack. It handles the dirty work. / Saves state and calls user function. sigsave: dec r15, $12 / make room on stack ldm (rr14), r0, $6 / save r0-r5 ld r3, rr14(12) / get signo (pushed by system) push (rr14), r3 / pass to user function add r3, r3 / multiply r3 add r3, r3 / times 4 sub r2, r2 / clear high half of rr2 addl rr2, $sigtable-4 / ldl rr2, (rr2) call (rr2) / (*sigtable[signo-1])(signo) inc r15, $2 ld r0, rr14(14) / get indicator flags ldctlb FLAGS, rl0 / restore them ldm r0, (rr14), $6 / restore r0-r5 lda rr14, rr14(16) / pop stack, don't disturb indicators ret .prvd sigtable: .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1 .long -1