Mark
53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
#include "user/errno.h"
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#include "sys/block/blk.h"
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#include "sys/string.h"
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#include "sys/panic.h"
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#include "sys/attr.h"
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#include "sys/dev.h"
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#define DEV_ZERO 0
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#define DEV_NULL 1
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static ssize_t pseudo_write(struct blkdev *dev, const void *buf, size_t pos, size_t lim);
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static ssize_t pseudo_read(struct blkdev *dev, void *buf, size_t pos, size_t lim);
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static struct blkdev _dev_null = {
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.dev_data = (void *) DEV_NULL,
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.write = pseudo_write,
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.read = pseudo_read
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};
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static struct blkdev _dev_zero = {
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.dev_data = (void *) DEV_ZERO,
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.write = pseudo_write,
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.read = pseudo_read
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};
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static ssize_t pseudo_write(struct blkdev *dev, const void *buf, size_t pos, size_t lim) {
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switch ((uint64_t) dev->dev_data) {
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case DEV_NULL:
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case DEV_ZERO:
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return lim;
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default:
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panic("Unexpected dev id: %p\n", dev->dev_data);
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}
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}
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static ssize_t pseudo_read(struct blkdev *dev, void *buf, size_t pos, size_t lim) {
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switch ((uint64_t) dev->dev_data) {
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case DEV_ZERO:
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memset(buf, 0, lim);
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return lim;
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case DEV_NULL:
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return 0;
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default:
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panic("Unexpected dev id: %p\n", dev->dev_data);
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}
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}
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// XXX: This is called before heap init, fucked up?
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void pseudo_init(void) {
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// FIXME: They're actually character devices
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dev_add(DEV_CLASS_BLOCK, DEV_BLOCK_PSEUDO, &_dev_null, "null");
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dev_add(DEV_CLASS_BLOCK, DEV_BLOCK_PSEUDO, &_dev_zero, "zero");
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}
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