59 lines
1.2 KiB
C
59 lines
1.2 KiB
C
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// Fake IDE disk; stores blocks in memory.
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// Useful for running kernel without scratch disk.
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#include "types.h"
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#include "defs.h"
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#include "param.h"
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#include "mmu.h"
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#include "proc.h"
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#include "x86.h"
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#include "traps.h"
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#include "spinlock.h"
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#include "buf.h"
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extern uchar _binary_fs_img_start[], _binary_fs_img_size[];
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static int disksize;
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static uchar *memdisk;
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void
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ideinit(void)
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{
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memdisk = _binary_fs_img_start;
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disksize = (uint)_binary_fs_img_size/512;
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}
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// Interrupt handler.
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void
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ideintr(void)
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{
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// no-op
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}
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// Sync buf with disk.
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// If B_DIRTY is set, write buf to disk, clear B_DIRTY, set B_VALID.
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// Else if B_VALID is not set, read buf from disk, set B_VALID.
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void
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iderw(struct buf *b)
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{
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uchar *p;
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if(!(b->flags & B_BUSY))
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panic("iderw: buf not busy");
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if((b->flags & (B_VALID|B_DIRTY)) == B_VALID)
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panic("iderw: nothing to do");
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if(b->dev != 1)
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panic("iderw: request not for disk 1");
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if(b->sector >= disksize)
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panic("iderw: sector out of range");
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p = memdisk + b->sector*512;
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if(b->flags & B_DIRTY){
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b->flags &= ~B_DIRTY;
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memmove(p, b->data, 512);
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} else
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memmove(b->data, p, 512);
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b->flags |= B_VALID;
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}
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