Printing the trace output buffer contents
Your routine must update the trace output buffer with the user data and call the print buffer service routine, IEAVETPB, to print each output line.
IEAVETPB, entry point in module IEAVETFA, prints the trace output buffer. In the case of a print dump request, IEAVETPB also keeps track of the number of lines printed on a page and skips to a new page when the maximum has been printed or the TTE being printed requires more than the lines left on the page.
When your USRn formatting routine passes control to IEAVETPB, the
input registers must contain the following values:
- Register
- Contents
- 1
- Address of a five-fullword parameter list
- 13
- Address of save area
- 14
- Return address
- 15
- Address of entry point
The parameter list in register 1 contains:
- Address of the token received from the system. If it does not receive the token, it issues a X'09E' ABEND with a reason code of X'00005301', and the system trace formatter terminates.
- Address of the trace output buffer (TROB). It locates the output line to be printed using the address in the second parameter.
- Address of the relative output line number. The third parameter is the relative output line number for the formatting of a single TTE. The value in this parameter indicates which line this is of the total number of output lines needed to format the TTE.
- Address of the number of output lines expected. The fourth parameter is the total number of lines needed to format the TTE; that is, the number of times the USRn formatting routine will call IEAVETPB to print a particular TTE.
- Address of the print option for this call. The fifth parameter
indicates the kind of output contained in the trace output buffer:
- X'80000000' means the output buffer contains a TTE
- X'00000000' means the output buffer contains a message
Having printed a line of output, IEAVETPB returns to the USRn formatting routine with a return code of zero in register 15.