/*
 * Copyright (c) 2018-2019 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 <mesosphere.hpp>

namespace ams::kern::init::Elf::Elf64 {

	/* API to apply relocations or call init array. */
	void ApplyRelocations(uintptr_t base_address, const Dyn *dynamic) {
		uintptr_t dyn_rel    = 0;
		uintptr_t dyn_rela   = 0;
		uintptr_t rel_count  = 0;
		uintptr_t rela_count = 0;
		uintptr_t rel_ent    = 0;
		uintptr_t rela_ent   = 0;

		/* Iterate over all tags, identifying important extents. */
		for (const Dyn *cur_entry = dynamic; cur_entry->GetTag() != DT_NULL; cur_entry++) {
			switch (cur_entry->GetTag()) {
				case DT_REL:
					dyn_rel    = base_address + cur_entry->GetPtr();
					break;
				case DT_RELA:
					dyn_rela   = base_address + cur_entry->GetPtr();
					break;
				case DT_RELENT:
					rel_ent    = cur_entry->GetValue();
					break;
				case DT_RELAENT:
					rela_ent   = cur_entry->GetValue();
					break;
				case DT_RELCOUNT:
					rel_count  = cur_entry->GetValue();
					break;
				case DT_RELACOUNT:
					rela_count = cur_entry->GetValue();
					break;
			}
		}

		/* Apply all Rel relocations */
		for (size_t i = 0; i < rel_count; i++) {
			const auto &rel = *reinterpret_cast<const Elf64::Rel *>(dyn_rel + rel_ent * i);

			/* Only allow R_AARCH64_RELATIVE relocations. */
			while (rel.GetType() != R_AARCH64_RELATIVE) { /* ... */ }

			/* Apply the relocation. */
			Elf64::Addr *target_address = reinterpret_cast<Elf64::Addr *>(base_address + rel.GetOffset());
			*target_address += base_address;
		}

		/* Apply all Rela relocations. */
		for (size_t i = 0; i < rela_count; i++) {
			const auto &rela = *reinterpret_cast<const Elf64::Rela *>(dyn_rela + rela_ent * i);

			/* Only allow R_AARCH64_RELATIVE relocations. */
			while (rela.GetType() != R_AARCH64_RELATIVE) { /* ... */ }

			/* Apply the relocation. */
			Elf64::Addr *target_address = reinterpret_cast<Elf64::Addr *>(base_address + rela.GetOffset());
			*target_address = base_address + rela.GetAddend();
		}
	}

	void CallInitArrayFuncs(uintptr_t init_array_start, uintptr_t init_array_end) {

	}

}