9df1183b94
. added safecopies.c: these are library functions to maintain grant tables in own address space . sys_safecopy.c: interfaces to kernel calls to perform safe copy functions in from or to foreign process . changes in i/o fields (type merged with request) reflected in library functions (sys_out.c, sys_vinb.c, sys_vinl.c, sys_vinw.c, sys_voutb.c, sys_voutl.c, sys_voutw.c) . type merged with request in sys_sdevio, also now accepts offset which is used when a grant is specified (the _DIO_SAFE subtype) . system printf() function changed to send DIAGNOSTICS_S messages, which specify a grant id instead of a direct address for the buffer to be printed; tty and log can then safecopy the buffer
70 lines
2.2 KiB
C
70 lines
2.2 KiB
C
/* A server must occasionally print some message. It uses a simple version of
|
|
* printf() found in the system lib that calls kputc() to output characters.
|
|
* Printing is done with a call to the kernel, and not by going through FS.
|
|
*
|
|
* This routine can only be used by servers and device drivers. The kernel
|
|
* must define its own kputc(). Note that the log driver also defines its own
|
|
* kputc() to directly call the TTY instead of going through this library.
|
|
*/
|
|
|
|
#include "sysutil.h"
|
|
|
|
static char print_buf[80]; /* output is buffered here */
|
|
|
|
/*===========================================================================*
|
|
* kputc *
|
|
*===========================================================================*/
|
|
void kputc(c)
|
|
int c;
|
|
{
|
|
/* Accumulate another character. If 0 or buffer full, print it. */
|
|
static int buf_count; /* # characters in the buffer */
|
|
message m;
|
|
|
|
if ((c == 0 && buf_count > 0) || buf_count == sizeof(print_buf)) {
|
|
#define PRINTPROCS (sizeof(procs)/sizeof(procs[0]))
|
|
int procs[] = OUTPUT_PROCS_ARRAY;
|
|
static int firstprint = 1;
|
|
static cp_grant_t printgrant_buffer[PRINTPROCS];
|
|
static cp_grant_id_t printgrants[PRINTPROCS];
|
|
int p;
|
|
|
|
if(firstprint) {
|
|
/* First time? Initialize grant table;
|
|
* Grant printing processes read copy access to our
|
|
* print buffer. (So buffer can't be on stack!)
|
|
*/
|
|
cpf_preallocate(printgrant_buffer, PRINTPROCS);
|
|
for(p = 0; procs[p] != NONE; p++) {
|
|
printgrants[p] = cpf_grant_direct(procs[p], print_buf,
|
|
sizeof(print_buf), CPF_READ);
|
|
}
|
|
firstprint = 0;
|
|
}
|
|
|
|
for(p = 0; procs[p] != NONE; p++) {
|
|
/* Send the buffer to this output driver. */
|
|
m.DIAG_BUF_COUNT = buf_count;
|
|
if(GRANT_VALID(printgrants[p])) {
|
|
m.m_type = DIAGNOSTICS_S;
|
|
m.DIAG_PRINT_BUF_G = printgrants[p];
|
|
} else {
|
|
m.m_type = DIAGNOSTICS;
|
|
m.DIAG_PRINT_BUF_G = print_buf;
|
|
}
|
|
(void) _sendrec(procs[p], &m);
|
|
}
|
|
|
|
buf_count = 0;
|
|
|
|
/* If the output fails, e.g., due to an ELOCKED, do not retry output
|
|
* at the FS as if this were a normal user-land printf(). This may
|
|
* result in even worse problems.
|
|
*/
|
|
}
|
|
if (c != 0) {
|
|
|
|
/* Append a single character to the output buffer. */
|
|
print_buf[buf_count++] = c;
|
|
}
|
|
}
|