181 lines
4.5 KiB
C++
181 lines
4.5 KiB
C++
/*
|
|
* \brief ROM filesystem
|
|
* \author Norman Feske
|
|
* \date 2014-04-14
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2014-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _INCLUDE__VFS__ROM_FILE_SYSTEM_H_
|
|
#define _INCLUDE__VFS__ROM_FILE_SYSTEM_H_
|
|
|
|
#include <base/attached_rom_dataspace.h>
|
|
#include <vfs/file_system.h>
|
|
|
|
namespace Vfs { class Rom_file_system; }
|
|
|
|
|
|
class Vfs::Rom_file_system : public Single_file_system
|
|
{
|
|
private:
|
|
|
|
enum Rom_type { ROM_TEXT, ROM_BINARY };
|
|
|
|
typedef String<64> Label;
|
|
|
|
Label const _label;
|
|
|
|
bool const _binary;
|
|
|
|
Genode::Attached_rom_dataspace _rom;
|
|
|
|
class Rom_vfs_handle : public Single_vfs_handle
|
|
{
|
|
private:
|
|
|
|
Genode::Attached_rom_dataspace &_rom;
|
|
|
|
file_size const _content_size;
|
|
|
|
file_size _init_content_size(Rom_type type)
|
|
{
|
|
if (type == ROM_TEXT) {
|
|
for (file_size pos = 0; pos < _rom.size(); pos++)
|
|
if (_rom.local_addr<char>()[pos] == 0x00)
|
|
return pos;
|
|
}
|
|
|
|
return _rom.size();
|
|
}
|
|
|
|
public:
|
|
|
|
Rom_vfs_handle(Directory_service &ds,
|
|
File_io_service &fs,
|
|
Genode::Allocator &alloc,
|
|
Genode::Attached_rom_dataspace &rom,
|
|
Rom_type type)
|
|
:
|
|
Single_vfs_handle(ds, fs, alloc, 0),
|
|
_rom(rom), _content_size(_init_content_size(type))
|
|
{ }
|
|
|
|
Read_result read(char *dst, file_size count,
|
|
file_size &out_count) override
|
|
{
|
|
/* file read limit is the size of the dataspace */
|
|
file_size const max_size = _content_size;
|
|
|
|
/* current read offset */
|
|
file_size const read_offset = seek();
|
|
|
|
/* maximum read offset, clamped to dataspace size */
|
|
file_size const end_offset = min(count + read_offset, max_size);
|
|
|
|
/* check if end of file is reached */
|
|
if (read_offset >= end_offset) {
|
|
out_count = 0;
|
|
return READ_OK;
|
|
}
|
|
|
|
/* source address within the dataspace */
|
|
char const *src = _rom.local_addr<char>() + read_offset;
|
|
|
|
/* copy-out bytes from ROM dataspace */
|
|
file_size const num_bytes = end_offset - read_offset;
|
|
|
|
memcpy(dst, src, num_bytes);
|
|
|
|
out_count = num_bytes;
|
|
return READ_OK;
|
|
}
|
|
|
|
Write_result write(char const *, file_size,
|
|
file_size &out_count) override
|
|
{
|
|
out_count = 0;
|
|
return WRITE_ERR_INVALID;
|
|
}
|
|
|
|
bool read_ready() override { return true; }
|
|
};
|
|
|
|
public:
|
|
|
|
Rom_file_system(Vfs::Env &env,
|
|
Genode::Xml_node config)
|
|
:
|
|
Single_file_system(Node_type::CONTINUOUS_FILE, name(),
|
|
Node_rwx::ro(), config),
|
|
|
|
/* use 'label' attribute if present, fall back to 'name' if not */
|
|
_label(config.attribute_value("label",
|
|
config.attribute_value("name", Label()))),
|
|
|
|
_binary(config.attribute_value("binary", true)),
|
|
|
|
_rom(env.env(), _label.string())
|
|
{ }
|
|
|
|
static char const *name() { return "rom"; }
|
|
char const *type() override { return "rom"; }
|
|
|
|
/*********************************
|
|
** Directory-service interface **
|
|
********************************/
|
|
|
|
Open_result open(char const *path, unsigned,
|
|
Vfs_handle **out_handle,
|
|
Allocator &alloc) override
|
|
{
|
|
if (!_single_file(path))
|
|
return OPEN_ERR_UNACCESSIBLE;
|
|
|
|
_rom.update();
|
|
|
|
try {
|
|
*out_handle = new (alloc)
|
|
Rom_vfs_handle(*this, *this, alloc, _rom, _binary ? ROM_BINARY : ROM_TEXT);
|
|
return OPEN_OK;
|
|
}
|
|
catch (Genode::Out_of_ram) { return OPEN_ERR_OUT_OF_RAM; }
|
|
catch (Genode::Out_of_caps) { return OPEN_ERR_OUT_OF_CAPS; }
|
|
}
|
|
|
|
Dataspace_capability dataspace(char const *) override
|
|
{
|
|
return _rom.cap();
|
|
}
|
|
|
|
/********************************
|
|
** File I/O service interface **
|
|
********************************/
|
|
|
|
Stat_result stat(char const *path, Stat &out) override
|
|
{
|
|
Stat_result const result = Single_file_system::stat(path, out);
|
|
|
|
/*
|
|
* If the stat call refers to our node ('Single_file_system::stat'
|
|
* found a file), obtain the size of the most current ROM module
|
|
* version.
|
|
*/
|
|
if (out.type == Node_type::CONTINUOUS_FILE) {
|
|
_rom.update();
|
|
out.size = _rom.valid() ? _rom.size() : 0;
|
|
out.rwx = { .readable = true,
|
|
.writeable = false,
|
|
.executable = true };
|
|
}
|
|
|
|
return result;
|
|
}
|
|
};
|
|
|
|
#endif /* _INCLUDE__VFS__ROM_FILE_SYSTEM_H_ */
|