124 lines
3.1 KiB
C
124 lines
3.1 KiB
C
/****************************************************************************/
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/*
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* uclinux.c -- generic memory mapped MTD driver for uclinux
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*
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* (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
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*/
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/****************************************************************************/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/major.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/map.h>
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#include <linux/mtd/partitions.h>
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#include <asm/io.h>
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#include <asm/sections.h>
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/****************************************************************************/
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struct map_info uclinux_ram_map = {
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.name = "RAM",
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.phys = (unsigned long)__bss_stop,
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.size = 0,
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};
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static struct mtd_info *uclinux_ram_mtdinfo;
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/****************************************************************************/
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static struct mtd_partition uclinux_romfs[] = {
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{ .name = "ROMfs" }
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};
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#define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs)
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/****************************************************************************/
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static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, void **virt, resource_size_t *phys)
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{
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struct map_info *map = mtd->priv;
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*virt = map->virt + from;
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if (phys)
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*phys = map->phys + from;
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*retlen = len;
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return(0);
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}
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/****************************************************************************/
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static int __init uclinux_mtd_init(void)
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{
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struct mtd_info *mtd;
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struct map_info *mapp;
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mapp = &uclinux_ram_map;
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if (!mapp->size)
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mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
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mapp->bankwidth = 4;
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printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
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(int) mapp->phys, (int) mapp->size);
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/*
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* The filesystem is guaranteed to be in direct mapped memory. It is
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* directly following the kernels own bss region. Following the same
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* mechanism used by architectures setting up traditional initrds we
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* use phys_to_virt to get the virtual address of its start.
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*/
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mapp->virt = phys_to_virt(mapp->phys);
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if (mapp->virt == 0) {
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printk("uclinux[mtd]: no virtual mapping?\n");
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return(-EIO);
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}
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simple_map_init(mapp);
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mtd = do_map_probe("map_ram", mapp);
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if (!mtd) {
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printk("uclinux[mtd]: failed to find a mapping?\n");
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return(-ENXIO);
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}
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mtd->owner = THIS_MODULE;
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mtd->_point = uclinux_point;
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mtd->priv = mapp;
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uclinux_ram_mtdinfo = mtd;
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mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
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return(0);
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}
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/****************************************************************************/
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static void __exit uclinux_mtd_cleanup(void)
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{
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if (uclinux_ram_mtdinfo) {
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mtd_device_unregister(uclinux_ram_mtdinfo);
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map_destroy(uclinux_ram_mtdinfo);
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uclinux_ram_mtdinfo = NULL;
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}
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if (uclinux_ram_map.virt)
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uclinux_ram_map.virt = 0;
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}
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/****************************************************************************/
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module_init(uclinux_mtd_init);
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module_exit(uclinux_mtd_cleanup);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
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MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
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/****************************************************************************/
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