csync(2)                          SDK R4.11                         csync(2)


NAME
       csync - synchronize hardware caches for execute access (88k only)

SYNOPSIS
       #include <sys/types.h>

       void csync (addr, len)
       caddrt addr;
       sizet  len;

DESCRIPTION
       The DG/UX system supports two methods for synchronizing hardware
       cache and memory contents: issuing a trap to vector 502, defined by
       the 88open Binary Compatibility Standard (BCS), revision 1.1A,
       chapter 9; and csync(2), defined by the System V Release 4
       Application Binary Interface (ABI): Motorola 88000 Processor
       Supplement.  If your program must be BCS-compliant, use the trap
       method. Otherwise, use csync(2) as explained below.

       The csync(2) call makes the designated memory region safe for
       execution in all executable mappings of the region, and safe for
       reading in all such mappings which have read and execute permission.

       addr  is the starting address of the memory region.

       len   is the length in bytes of the region.

       If len is 0, all addresses are designated. If len is not 0, the
       modulus sum of len and addr must exceed the value of addr. Otherwise,
       the results are undefined.

       On M88000 based systems (such as AViiON systems), programs that
       modify and execute memory need to invoke csync(2) just after the
       modification and prior to the execution.  Doing so notifies the
       system, and synchronizes the contents of memory with that of the
       caches.

       When several processes share a memory region, note:

       ·    Executable mappings of the shared region should include write
            access, to insure that reading is always safe.

       ·    At least one of the processes must invoke csync(2), following
            any modifications by the processes, and preceding execution by
            any of them.

ACCESS CONTROL
       None.

RETURN VALUE
       None.

DIAGNOSTICS
       None.

SEE ALSO
       memctl(2), mmap(2), mprotect(2), stkexec(2), stkprotect(2).


Licensed material--property of copyright holder(s)