1 /****************************************************************************/
4 * uclinux.c -- generic memory mapped MTD driver for uclinux
6 * (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
9 /****************************************************************************/
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
17 #include <linux/major.h>
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/partitions.h>
22 #include <asm/sections.h>
24 /****************************************************************************/
26 struct map_info uclinux_ram_map = {
28 .phys = (unsigned long)__bss_stop,
32 static struct mtd_info *uclinux_ram_mtdinfo;
34 /****************************************************************************/
36 static struct mtd_partition uclinux_romfs[] = {
40 #define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs)
42 /****************************************************************************/
44 static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
45 size_t *retlen, void **virt, resource_size_t *phys)
47 struct map_info *map = mtd->priv;
48 *virt = map->virt + from;
50 *phys = map->phys + from;
55 /****************************************************************************/
57 static int __init uclinux_mtd_init(void)
60 struct map_info *mapp;
62 mapp = &uclinux_ram_map;
64 mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
67 printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
68 (int) mapp->phys, (int) mapp->size);
71 * The filesystem is guaranteed to be in direct mapped memory. It is
72 * directly following the kernels own bss region. Following the same
73 * mechanism used by architectures setting up traditional initrds we
74 * use phys_to_virt to get the virtual address of its start.
76 mapp->virt = phys_to_virt(mapp->phys);
78 if (mapp->virt == 0) {
79 printk("uclinux[mtd]: no virtual mapping?\n");
83 simple_map_init(mapp);
85 mtd = do_map_probe("map_ram", mapp);
87 printk("uclinux[mtd]: failed to find a mapping?\n");
91 mtd->owner = THIS_MODULE;
92 mtd->_point = uclinux_point;
95 uclinux_ram_mtdinfo = mtd;
96 mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
101 /****************************************************************************/
103 static void __exit uclinux_mtd_cleanup(void)
105 if (uclinux_ram_mtdinfo) {
106 mtd_device_unregister(uclinux_ram_mtdinfo);
107 map_destroy(uclinux_ram_mtdinfo);
108 uclinux_ram_mtdinfo = NULL;
110 if (uclinux_ram_map.virt)
111 uclinux_ram_map.virt = 0;
114 /****************************************************************************/
116 module_init(uclinux_mtd_init);
117 module_exit(uclinux_mtd_cleanup);
119 MODULE_LICENSE("GPL");
120 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
121 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
123 /****************************************************************************/