drivers/tty/vt/conmakehash.c

Source file repositories/reference/linux-study-clean/drivers/tty/vt/conmakehash.c

File Facts

System
Linux kernel
Corpus path
drivers/tty/vt/conmakehash.c
Extension
.c
Size
5923 bytes
Lines
288
Domain
Driver Families
Bucket
drivers/tty
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * conmakehash.c
 *
 * Create arrays for initializing the kernel folded tables (using a hash
 * table turned out to be to limiting...)  Unfortunately we can't simply
 * preinitialize the tables at compile time since kfree() cannot accept
 * memory not allocated by kmalloc(), and doing our own memory management
 * just for this seems like massive overkill.
 *
 * Copyright (C) 1995-1997 H. Peter Anvin
 */

#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <string.h>
#include <ctype.h>

#define MAX_FONTLEN 256

typedef unsigned short unicode;

static void usage(char *argv0)
{
  fprintf(stderr, "Usage: \n"
         "        %s chartable [hashsize] [hashstep] [maxhashlevel]\n", argv0);
  exit(EX_USAGE);
}

static int getunicode(char **p0)
{
  char *p = *p0;

  while (*p == ' ' || *p == '\t')
    p++;
  if (*p != 'U' || p[1] != '+' ||
      !isxdigit(p[2]) || !isxdigit(p[3]) || !isxdigit(p[4]) ||
      !isxdigit(p[5]) || isxdigit(p[6]))
    return -1;
  *p0 = p+6;
  return strtol(p+2,0,16);
}

unicode unitable[MAX_FONTLEN][255];
				/* Massive overkill, but who cares? */
int unicount[MAX_FONTLEN];

static void addpair(int fp, int un)
{
  int i;

  if ( un <= 0xfffe )
    {
      /* Check it isn't a duplicate */

      for ( i = 0 ; i < unicount[fp] ; i++ )
	if ( unitable[fp][i] == un )
	  return;

      /* Add to list */

      if ( unicount[fp] > 254 )
	{
	  fprintf(stderr, "ERROR: Only 255 unicodes/glyph permitted!\n");
	  exit(EX_DATAERR);
	}

      unitable[fp][unicount[fp]] = un;
      unicount[fp]++;
    }

  /* otherwise: ignore */
}

int main(int argc, char *argv[])
{
  FILE *ctbl;
  const char *tblname;
  char buffer[65536];
  int fontlen;
  int i, nuni, nent;
  int fp0, fp1, un0, un1;
  char *p, *p1;

  if ( argc < 2 || argc > 5 )
    usage(argv[0]);

  if ( !strcmp(argv[1],"-") )
    {

Annotation

Implementation Notes