/*
* Copyright (c) 2007 Michal Konopa
* Copyright (c) 2007 Martin Jelen
* Copyright (c) 2007 Peter Majer
* Copyright (c) 2007 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup rd
* @{
*/
/**
* @file rd.c
* @brief Initial RAM disk for HelenOS.
*/
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <ipc/ns.h>
#include <sysinfo.h>
#include <as.h>
#include <ddi.h>
#include <align.h>
#include <bool.h>
#include <errno.h>
#include <async.h>
#include <align.h>
#include <async.h>
#include <futex.h>
#include <stdio.h>
#include <devmap.h>
#include <ipc/bd.h>
#define NAME "rd"
/** Pointer to the ramdisk's image. */
static void *rd_addr;
/** Size of the ramdisk. */
static size_t rd_size;
/**
* This futex protects the ramdisk's data.
* If we were to serve multiple requests (read + write or several writes)
* concurrently (i.e. from two or more threads), each read and write needs to be
* protected by this futex.
*/
atomic_t rd_futex = FUTEX_INITIALIZER;
/** Handle one connection to ramdisk.
*
* @param iid Hash of the request that opened the connection.
* @param icall Call data of the request that opened the connection.
*/
static void rd_connection(ipc_callid_t iid, ipc_call_t *icall)
{
ipc_callid_t callid;
ipc_call_t call;
int retval;
void *fs_va = NULL;
off_t offset;
size_t block_size;
size_t maxblock_size;
/*
* Answer the first IPC_M_CONNECT_ME_TO call.
*/
ipc_answer_0(iid, EOK);
/*
* Now we wait for the client to send us its communication as_area.
*/
int flags;
if (ipc_share_out_receive(&callid, &maxblock_size, &flags)) {
fs_va = as_get_mappable_page(maxblock_size);
if (fs_va) {
(void) ipc_share_out_finalize(callid, fs_va);
} else {
ipc_answer_0(callid, EHANGUP);
return;
}
} else {
/*
* The client doesn't speak the same protocol.
* At this point we can't handle protocol variations.
* Close the connection.
*/
ipc_answer_0(callid, EHANGUP);
return;
}
while (1) {
callid = async_get_call(&call);
switch (IPC_GET_METHOD(call)) {
case IPC_M_PHONE_HUNGUP:
/*
* The other side has hung up.
* Answer the message and exit the fibril.
*/
ipc_answer_0(callid, EOK);
return;
case BD_READ_BLOCK:
offset = IPC_GET_ARG1(call);
block_size = IPC_GET_ARG2(call);
if (block_size > maxblock_size) {
/*
* Maximum block size exceeded.
*/
retval = ELIMIT;
break;
}
if (offset * block_size > rd_size - block_size) {
/*
* Reading past the end of the device.
*/
retval = ELIMIT;
break;
}
futex_down(&rd_futex);
memcpy(fs_va
, rd_addr
+ offset
* block_size
, block_size
); futex_up(&rd_futex);
retval = EOK;
break;
case BD_WRITE_BLOCK:
offset = IPC_GET_ARG1(call);
block_size = IPC_GET_ARG2(call);
if (block_size > maxblock_size) {
/*
* Maximum block size exceeded.
*/
retval = ELIMIT;
break;
}
if (offset * block_size > rd_size - block_size) {
/*
* Writing past the end of the device.
*/
retval = ELIMIT;
break;
}
futex_up(&rd_futex);
memcpy(rd_addr
+ offset
* block_size
, fs_va
, block_size
); futex_down(&rd_futex);
retval = EOK;
break;
default:
/*
* The client doesn't speak the same protocol.
* Instead of closing the connection, we just ignore
* the call. This can be useful if the client uses a
* newer version of the protocol.
*/
retval = EINVAL;
break;
}
ipc_answer_0(callid, retval);
}
}
/** Prepare the ramdisk image for operation. */
static bool rd_init(void)
{
rd_size = sysinfo_value("rd.size");
void *rd_ph_addr = (void *) sysinfo_value("rd.address.physical");
if (rd_size == 0) {
printf(NAME
": No RAM disk found\n"); return false;
}
rd_addr = as_get_mappable_page(rd_size);
int flags = AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE;
int retval = physmem_map(rd_ph_addr, rd_addr,
ALIGN_UP(rd_size, PAGE_SIZE) >> PAGE_WIDTH, flags);
if (retval < 0) {
printf(NAME
": Error mapping RAM disk\n"); return false;
}
printf(NAME
": Found RAM disk at %p, %d bytes\n", rd_ph_addr
, rd_size
);
int driver_phone = devmap_driver_register(NAME, rd_connection);
if (driver_phone < 0) {
printf(NAME
": Unable to register driver\n"); return false;
}
dev_handle_t dev_handle;
if (devmap_device_register(driver_phone, "initrd", &dev_handle) != EOK) {
ipc_hangup(driver_phone);
printf(NAME
": Unable to register device\n"); return false;
}
/*
* Create the second device.
* We need at least two devices for the sake of testing of non-root
* mounts. Of course it would be better to allow the second device
* be created dynamically...
*/
if (devmap_device_register(driver_phone, "spared", &dev_handle) != EOK) {
ipc_hangup(driver_phone);
printf(NAME
": Unable to register device\n"); return false;
}
return true;
}
int main(int argc, char **argv)
{
printf(NAME
": HelenOS RAM disk server\n");
if (!rd_init())
return -1;
printf(NAME
": Accepting connections\n"); async_manager();
/* Never reached */
return 0;
}
/**
* @}
*/