User guide

38 CHAPTER 3. THE LIBRARY
rtn
hdrsvar CIN:y, POS:y, NAT:n
This field holds the name of the environment variable givin g the di r ec t or i es holding
BCPL header s , typically ”BCPLHDRS” or ”PO SHD RS”. See Section 3.6 for more
details.
rtn idletcb CIN:n, POS:y, NAT:n
This ro ot node field holds th e TCB of the IDLE task for used by the standalone
debugger and the commands dumpsys and dumpdebug. The task number of the IDLE
task is zer o but it is not a prop er task and does not have an entry in the task table.
The Cintpos scheduler give it control when all other tasks are suspended.
rtn
info CIN:y, POS:y, NAT:n
This rootnode field holds a vector of information that can be shared between all
tasks. It is typically a vector of 50 elements. The use of t he se elements are system
dependent .
rtn insadebug CIN:n, POS:y, NAT:n
This rootnode field is used by the keyboard input device of Cintp os to tell it wh et he r
to place a newly received char ac te r in a r eq u es t packet or just store it in the lastch
field.
rtn intflag CIN:y, POS:y, NAT:n
This flag is set to TRUE on receiving an interrupt from the user (typically a SIGINT
signal generated by ct r l -C) and is reset to FALSE whenever the standalone debugger is
entered. Cintsys or cintpos exits if a user interrupt is received whe n intflag is TRUE
or if control is within BOOT or sadebug.
rtn
keyboard CIN:y, POS:y, NAT:n
This rootnode field holds the stream control block for the standard keyboard de v i c e.
rtn
klib CIN:y, POS:y, NAT:n
Under Cintpos this rootnode filed holds the the KLIB module. It is otherwise zero.
rtn
lastch CIN:n, POS:y, NAT:n
This rootnode field holds the most recent character received from the keyboard
device. The standalone debugger uses it for polling input. On reading this field the
standalone debugger resets it to pollingch=-3.
rtn lastg, rtn lastp, rtn lastst CIN:y, POS:y, NAT:n
These rootnode fields hold the most recent settings of the Cintcode P, G and ST
registers. They are used by the commands dumpsys and dumpdebug when inspecting a
Cintcode memory dump caused by faults such as memory violation (SIGSEGV) when
all other Cintcode dumped registers are invalid.
rtn
mc0, rtn m c1, rtn mc2, rtn mc3 CIN:y, POS:y, NAT:n
These hold the machine address of the start of the Cintcode memor y and other
values used by the MC package.