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Atmosphere/libraries/libstratosphere/source/os/os_stratosphere_api.os.horizon.cpp
2021-10-07 17:44:54 -07:00

172 lines
5.6 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "impl/os_resource_manager.hpp"
extern "C" { extern u8 __argdata__[]; }
namespace ams::os {
namespace {
class MemoryArranger {
private:
uintptr_t m_address;
public:
constexpr MemoryArranger(uintptr_t address) : m_address(address) { /* ... */ }
template<typename T>
T *Arrange() {
this->Align(alignof(T));
return static_cast<T *>(this->Arrange(sizeof(T)));
}
void *Arrange(size_t size) {
const auto address = m_address;
m_address += size;
return reinterpret_cast<void *>(address);
}
void Align(size_t align) {
m_address = util::AlignUp(m_address, align);
}
char *ArrangeCharArray(size_t size) {
return reinterpret_cast<char *>(Arrange(size));
}
};
bool HasArguments(uintptr_t args_region) {
/* Check that the arguments region is read-write. */
svc::MemoryInfo mi;
svc::PageInfo pi;
if (R_FAILED(svc::QueryMemory(std::addressof(mi), std::addressof(pi), args_region))) {
return false;
}
return mi.permission == svc::MemoryPermission_ReadWrite;
}
const char *SkipSpace(const char *p, const char *end) {
while (p < end && std::isspace(*p)) { ++p; }
return p;
}
const char *GetTokenEnd(const char *p, const char *end) {
while (p < end && !std::isspace(*p)) { ++p; }
return p;
}
const char *GetQuotedTokenEnd(const char *p, const char *end) {
while (p < end && *p != '"') { ++p; }
return p;
}
int MakeArgv(char **out_argv_buf, char *arg_buf, const char *cmd_line, size_t cmd_line_size, int arg_max) {
/* Prepare to parse arguments. */
auto idx = 0;
auto src = cmd_line;
auto dst = arg_buf;
const auto end = src + cmd_line_size;
/* Parse all tokens. */
while (true) {
/* Advance past any spaces. */
src = SkipSpace(src, end);
if (src >= end) {
break;
}
/* Check that we don't have too many arguments. */
if (idx >= arg_max) {
break;
}
/* Find the start/end of the current argument token. */
const char *arg_end;
const char *src_next;
if (*src == '"') {
++src;
arg_end = GetQuotedTokenEnd(src, end);
src_next = arg_end + 1;
} else {
arg_end = GetTokenEnd(src, end);
src_next = arg_end;
}
/* Determine token size. */
const auto arg_size = arg_end - src;
/* Set the argv pointer. */
out_argv_buf[idx++] = dst;
/* Copy the argument. */
std::memcpy(dst, src, arg_size);
dst += arg_size;
/* Null-terminate the argument token. */
*(dst++) = '\x00';
/* Advance to next token. */
src = src_next;
}
/* Null terminate the final token. */
*(dst++) = '\x00';
/* Null terminate argv. */
out_argv_buf[idx] = nullptr;
return idx;
}
}
void SetHostArgc(int argc);
void SetHostArgv(char **argv);
void InitializeForStratosphereInternal() {
/* Initialize the global os resource manager. */
os::impl::ResourceManagerHolder::InitializeResourceManagerInstance();
/* Setup host argc/argv as needed. */
const uintptr_t args_region = reinterpret_cast<uintptr_t>(__argdata__);
if (HasArguments(args_region)) {
/* Create arguments memory arranger. */
MemoryArranger arranger(args_region);
/* Arrange. */
const auto &header = *arranger.Arrange<ldr::ProgramArguments>();
const char *cmd_line = arranger.ArrangeCharArray(header.arguments_size);
char *arg_buf = arranger.ArrangeCharArray(header.arguments_size + 2);
char **argv_buf = arranger.Arrange<char *>();
/* Determine extents. */
const auto arg_buf_size = reinterpret_cast<uintptr_t>(argv_buf) - args_region;
const auto arg_max = (header.allocated_size - arg_buf_size) / sizeof(char *);
/* Make argv. */
const auto arg_count = MakeArgv(argv_buf, arg_buf, cmd_line, header.arguments_size, arg_max);
/* Set host argc/argv. */
os::SetHostArgc(arg_count);
os::SetHostArgv(argv_buf);
}
}
}