Files
codezero/tasks/blkdev0/src/ramdisk.c
Bahadir Balban cab2e8bdd3 Finished adding untested bare functionality vfs
Finished adding untested shm syscalls.
Finished adding untested l4 send/recv helpers

Everything compiles. Now going to fix lots of bugs ;-)
2008-02-03 17:42:38 +00:00

117 lines
2.8 KiB
C

/*
* A basic ramdisk implementation.
*
* Copyright (C) 2007, 2008 Bahadir Balban
*
* The ramdisk binary is embedded in the data section of the ramdisk device
* executable. Read/writes simply occur to this area. The disk area could
* have any filesystem layout e.g. romfs, which is irrelevant for this code.
*/
#include <blkdev.h>
#include <ramdisk.h>
#include <l4/macros.h>
#include <l4/config.h>
#include <l4/types.h>
#include <string.h>
#include INC_SUBARCH(mm.h)
#include INC_GLUE(memory.h)
/* Ramdisk section markers for ramdisk inside this executable image */
extern char _start_ramdisk0[];
extern char _end_ramdisk0[];
extern char _start_ramdisk1[];
extern char _end_ramdisk1[];
struct ramdisk_data {
u64 base;
u64 end;
};
struct ramdisk_data rddata[2];
__attribute__((section(".data.sfs"))) char sfsdisk[SZ_16MB];
int ramdisk_init(struct block_device *ramdisk)
{
struct ramdisk_data *rddata = ramdisk->private;
if (!strcmp("ramdisk0", ramdisk->name)) {
rddata->base = (u64)(unsigned long)_start_ramdisk0;
rddata->end = (u64)(unsigned long)_end_ramdisk0;
ramdisk->size = (u64)((unsigned long)_end_ramdisk0 -
(unsigned long)_start_ramdisk0);
} else if (!strcmp("ramdisk1", ramdisk->name)) {
rddata->base = (u64)(unsigned long)_start_ramdisk1;
rddata->end = (u64)(unsigned long)_end_ramdisk1;
ramdisk->size = (u64)((unsigned long)_end_ramdisk1 -
(unsigned long)_start_ramdisk1);
} else
return -1;
return 0;
}
int ramdisk_open(struct block_device *ramdisk)
{
return 0;
}
int ramdisk_read(struct block_device *b, unsigned long offset, int size, void *buf)
{
struct ramdisk_data *data = b->private;
void *src = (void *)(unsigned long)(data->base + offset);
memcpy(buf, src, size);
return 0;
}
int ramdisk_write(struct block_device *b, unsigned long offset,
int size, void *buf)
{
struct ramdisk_data *data = b->private;
void *dst = (void *)(unsigned long)(data->base + offset);
memcpy(dst, buf, size);
return 0;
}
int ramdisk_readpage(struct block_device *b, unsigned long pfn, void *buf)
{
ramdisk_read(b, __pfn_to_addr(pfn), PAGE_SIZE, buf);
return 0;
}
int ramdisk_writepage(struct block_device *b, unsigned long pfn, void *buf)
{
ramdisk_write(b, __pfn_to_addr(pfn), PAGE_SIZE, buf);
return 0;
}
struct block_device ramdisk[2] = {
[0] = {
.name = "ramdisk0",
.private = &rddata[0],
.ops = {
.init = ramdisk_init,
.open = ramdisk_open,
.read = ramdisk_read,
.write = ramdisk_write,
.read_page = ramdisk_readpage,
.write_page = ramdisk_writepage,
},
},
[1] = {
.name = "ramdisk1",
.private = &rddata[1],
.ops = {
.init = ramdisk_init,
.open = ramdisk_open,
.read = ramdisk_read,
.write = ramdisk_write,
.read_page = ramdisk_readpage,
.write_page = ramdisk_writepage,
},
}
};