diff options
Diffstat (limited to 'user/init.c')
| -rw-r--r-- | user/init.c | 185 |
1 files changed, 0 insertions, 185 deletions
diff --git a/user/init.c b/user/init.c deleted file mode 100644 index be8e393..0000000 --- a/user/init.c +++ /dev/null @@ -1,185 +0,0 @@ -#include <common.h> - -/** -** Initial process; it starts the other top-level user processes. -** -** Prints a message at startup, '+' after each user process is spawned, -** and '!' before transitioning to wait() mode to the SIO, and -** startup and transition messages to the console. It also reports -** each child process it collects via wait() to the console along -** with that child's exit status. -*/ - -/* -** "Spawn table" process entry. Similar to the one in shell.c, but -** this version has a field to hold the PID of the spawned process -** to allow 'init' to respawn it when it terminates. -*/ -typedef struct proc_s { - uint_t index; // process table index - uint_t pid; // its PID (when spawned) - uint8_t e_prio; // process priority - char select[3]; // identifying character, NUL, extra - char *args[N_ARGS]; // argument vector strings -} proc_t; - -/* -** Create a spawn table entry for a process with a string literal -** as its argument buffer. We rely on the fact that the C standard -** ensures our array of pointers will be filled out with NULLs -*/ -#define PROCENT(e, p, s, ...) \ - { \ - e, 0, p, s, \ - { \ - __VA_ARGS__, NULL \ - } \ - } - -// sentinel value for the end of the table - must be updated -// if you have more than 90,210 user programs in the table -#define TBLEND 90210 - -/* -** This table contains one entry for each process that should be -** started by 'init'. Typically, this includes the 'idle' process -** and a 'shell' process. -*/ -static proc_t spawn_table[] = { - - // the idle process; it runs at Deferred priority, - // so it will only be dispatched when there is - // nothing else available to be dispatched - PROCENT(Idle, PRIO_DEFERRED, "!", "idle", "."), - - // the user shell - PROCENT(Shell, PRIO_STD, "@", "shell"), - - // PROCENT( 0, 0, 0, 0 ) - { TBLEND } -}; - -// character to be printed by init when it spawns a process -static char ch = '+'; - -/** -** process - spawn all user processes listed in the supplied table -** -** @param proc pointer to the spawn table entry to be used -*/ - -static void process(proc_t *proc) -{ - char buf[128]; - - // kick off the process - int32_t p = fork(); - if (p < 0) { - // error! - sprint(buf, "INIT: fork for #%d failed\n", (uint32_t)(proc->index)); - cwrites(buf); - - } else if (p == 0) { - // change child's priority - (void)setprio(proc->e_prio); - - // now, send it on its way - exec(proc->index, proc->args); - - // uh-oh - should never get here! - sprint(buf, "INIT: exec(0x%08x) failed\n", (uint32_t)(proc->index)); - cwrites(buf); - - } else { - // parent just reports that another one was started - swritech(ch); - - proc->pid = p; - } -} - -/* -** The initial user process. Should be invoked with zero or one -** argument; if provided, the first argument should be the ASCII -** character 'init' will print to indicate the spawning of a process. -*/ -USERMAIN(main) -{ - char buf[128]; - - // check to see if we got a non-standard "spawn" character - if (argc > 1) { - // maybe - check it to be sure it's printable - uint_t i = argv[1][0]; - if (i > ' ' && i < 0x7f) { - ch = argv[1][0]; - } - } - - cwrites("Init started\n"); - - // home up, clear on a TVI 925 - swritech('\x1a'); - - // wait a bit - DELAY(SHORT); - - // a bit of Dante to set the mood :-) - swrites("\n\nSpem relinquunt qui huc intrasti!\n\n\r"); - - /* - ** Start all the user processes - */ - - cwrites("INIT: starting user processes\n"); - - proc_t *next; - for (next = spawn_table; next->index != TBLEND; ++next) { - process(next); - } - - swrites(" !!!\r\n\n"); - - /* - ** At this point, we go into an infinite loop waiting - ** for our children (direct, or inherited) to exit. - */ - - cwrites("INIT: transitioning to wait() mode\n"); - - for (;;) { - int32_t status; - int whom = waitpid(0, &status); - - // PIDs must be positive numbers! - if (whom <= 0) { - sprint(buf, "INIT: waitpid() returned %d???\n", whom); - cwrites(buf); - } else { - // got one; report it - sprint(buf, "INIT: pid %d exit(%d)\n", whom, status); - cwrites(buf); - - // figure out if this is one of ours - for (next = spawn_table; next->index != TBLEND; ++next) { - if (next->pid == whom) { - // one of ours - reset the PID field - // (in case the spawn attempt fails) - next->pid = 0; - // and restart it - process(next); - break; - } - } - } - } - - /* - ** SHOULD NEVER REACH HERE - */ - - cwrites("*** INIT IS EXITING???\n"); - exit(1); - - return (1); // shut the compiler up -} |