mirror of https://github.com/ipxe/ipxe.git
92 lines
2.5 KiB
C
92 lines
2.5 KiB
C
/*
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* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <gpxe/blockdev.h>
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#include <gpxe/ramdisk.h>
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/**
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* @file
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*
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* RAM disks
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*
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*/
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static inline __attribute__ (( always_inline )) struct ramdisk *
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block_to_ramdisk ( struct block_device *blockdev ) {
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return container_of ( blockdev, struct ramdisk, blockdev );
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}
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/**
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* Read block
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*
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* @v blockdev Block device
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* @v block Block number
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* @v count Block count
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* @v buffer Data buffer
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* @ret rc Return status code
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*/
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static int ramdisk_read ( struct block_device *blockdev, uint64_t block,
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unsigned long count, userptr_t buffer ) {
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struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
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unsigned long offset = ( block * blockdev->blksize );
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unsigned long length = ( count * blockdev->blksize );
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DBGC ( ramdisk, "RAMDISK %p reading [%lx,%lx)\n",
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ramdisk, offset, length );
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memcpy_user ( buffer, 0, ramdisk->data, offset, length );
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return 0;
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}
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/**
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* Write block
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*
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* @v blockdev Block device
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* @v block Block number
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* @v count Block count
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* @v buffer Data buffer
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* @ret rc Return status code
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*/
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static int ramdisk_write ( struct block_device *blockdev, uint64_t block,
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unsigned long count, userptr_t buffer ) {
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struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
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unsigned long offset = ( block * blockdev->blksize );
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unsigned long length = ( count * blockdev->blksize );
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DBGC ( ramdisk, "RAMDISK %p writing [%lx,%lx)\n",
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ramdisk, offset, length );
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memcpy_user ( ramdisk->data, offset, buffer, 0, length );
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return 0;
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}
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int init_ramdisk ( struct ramdisk *ramdisk, userptr_t data, size_t len,
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unsigned int blksize ) {
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if ( ! blksize )
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blksize = 512;
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ramdisk->data = data;
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ramdisk->blockdev.read = ramdisk_read;
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ramdisk->blockdev.write = ramdisk_write;
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ramdisk->blockdev.blksize = blksize;
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ramdisk->blockdev.blocks = ( len / blksize );
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return 0;
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}
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