0e2a7a9730
Reduced kernel size by 512KB by moving private buffer into cstart() function. Replaced assertions with erroneous return values. Removed assertions relating to isuserp(rp), since all processes should become user processes; system processes are now treated similar to other processes.
83 lines
2.3 KiB
C
Executable file
83 lines
2.3 KiB
C
Executable file
/* This file contains a collection of miscellaneous procedures:
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* panic abort MINIX due to a fatal error
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* alloc_bit bit map manipulation
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* free_bit bit map manipulation
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*/
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#include "kernel.h"
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#include "assert.h"
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#include <unistd.h>
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#include <minix/com.h>
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/*===========================================================================*
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* panic *
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*===========================================================================*/
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PUBLIC void panic(s,n)
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_CONST char *s;
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int n;
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{
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/* The system has run aground of a fatal kernel error. Terminate execution. */
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static int panicking = 0;
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if (panicking ++) /* prevent recursive panics */
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return;
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if (s != NULL) {
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kprintf("\nKernel panic: %s", karg(s));
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if (n != NO_NUM) kprintf(" %d", n);
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kprintf("\n",NO_ARG);
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}
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prepare_shutdown(RBT_PANIC);
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}
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/*===========================================================================*
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* free_bit *
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*===========================================================================*/
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PUBLIC void free_bit(bit_nr, bitmap, nr_bits)
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bit_t bit_nr;
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bitchunk_t *bitmap;
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bit_t nr_bits;
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{
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bitchunk_t *chunk;
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if (bit_nr >= nr_bits) {
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kprintf("Warning, free_bit: %d illegal index\n", bit_nr);
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return;
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}
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chunk = &bitmap[(bit_nr/BITCHUNK_BITS)];
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*chunk &= ~(1 << (bit_nr % BITCHUNK_BITS));
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}
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/*===========================================================================*
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* alloc_bit *
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*===========================================================================*/
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PUBLIC int alloc_bit(bitmap, nr_bits)
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bitchunk_t *bitmap;
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bit_t nr_bits;
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{
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bitchunk_t *chunk;
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int nr_chunks;
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int bit_nr;
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int i;
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/* Iterate over the words in block. */
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nr_chunks = BITMAP_CHUNKS(nr_bits);
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for (chunk = &bitmap[0]; chunk < &bitmap[nr_chunks]; chunk++) {
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/* Does this chunk contain a free bit? */
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if (*chunk == (bitchunk_t) ~0) continue;
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/* Get bit number from the start of the bit map. */
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for (i = 0; (*chunk & (1 << i)) != 0; ++i) {}
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bit_nr = (chunk - &bitmap[0]) * BITCHUNK_BITS + i;
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/* Don't allocate bits beyond the end of the map. */
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if (bit_nr >= nr_bits) break;
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*chunk |= 1 << bit_nr % BITCHUNK_BITS;
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return(bit_nr);
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}
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return(-1);
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}
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