/* * \brief Stub for compiling GCC support libraries without libc * \author Norman Feske * \date 2011-08-31 * * The target components of GCC tool chains (i.e. libsupc++, libgcc_eh, and * libstdc++) depend on the presence of libc includes. For this reason, a C * library for the target platform is normally regarded as a prerequisite for * building a complete tool chain. However, for low-level operating-system * code, this prerequisite is not satisfied. * * There are two traditional solutions to this problem. The first is to leave * out those target components from the tool chain and live without full C++ * support (using '-fno-rtti' and '-fno-exceptions'). Because Genode relies on * such C++ features however, this is no option. The other traditional solution * is to use a tool chain compiled for a different target platform such as * Linux. However, this approach calls for subtle problems because the target * components are compiled against glibc and make certain presumptions about * the underlying OS environment. E.g., the 'libstdc++' library of a Linux tool * chain contains references to glibc's 'stderr' symbol, which does not exist * on Genode's libc derived from FreeBSD. More critical assumptions are related * to the mechanism used for thread-local storage. * * This header file overcomes these problems by providing all function * prototypes and type declarations that are mandatory for compiling GCC's * target components. Using this libc stub, all GCC target components can be * built without the need for additional libc support. Of course, for actually * using these target components, the target OS has to provide the * implementation of a small subset of functions declared herein. On Genode, * this subset is provided by the 'cxx' library. * * The code of the target components expects usual C header file names such as * 'stdio.h'. It does not include 'libgcc_libc_stub.h'. By creating symlinks * for all those file names pointing to this file, we ensure that this file is * always included on the first occurrence of the inclusion of any libc header * file. The set of symlinks pointing to this libc stub are created * automatically by the 'tool_chain' script. */ /* * Copyright (C) 2011-2013 Genode Labs GmbH * * This file is part of the Genode OS framework, which is distributed * under the terms of the GNU General Public License version 2. */ #ifndef _LINK_H_ #define _LINK_H_ #include <stddef.h> /***************** ** sys/types.h ** *****************/ #ifdef _LP64 typedef signed char __int8_t; typedef signed short __int16_t; typedef signed int __int32_t; typedef signed long __int64_t; typedef unsigned char __uint8_t; typedef unsigned short __uint16_t; typedef unsigned int __uint32_t; typedef unsigned long __uint64_t; #else /* _LP64 */ typedef signed char __int8_t; typedef signed short __int16_t; typedef signed long __int32_t; typedef unsigned char __uint8_t; typedef unsigned short __uint16_t; typedef unsigned long __uint32_t; #ifndef __STRICT_ANSI__ typedef signed long long __int64_t; typedef unsigned long long __uint64_t; #endif /* __STRICT_ANSI__ */ #endif /* _LP64 */ /*********** ** elf.h ** ***********/ /* * The following defines and types are solely needed to compile libgcc's * 'unwind-dw2-fde-glibc.c' in libc mode. This is needed because Genode's * dynamic linker relies on the the "new" exception mechanism, which is not * compiled-in when compiling libgcc with the 'inhibit_libc' flag. * * The following types are loosely based on glibc's 'link.h' and 'elf.h'. */ typedef __uint32_t Elf64_Word; typedef __uint64_t Elf64_Addr; typedef __uint64_t Elf64_Xword; typedef __uint64_t Elf64_Off; typedef __uint16_t Elf64_Half; typedef struct { Elf64_Word p_type; Elf64_Word p_flags; Elf64_Off p_offset; Elf64_Addr p_vaddr; Elf64_Addr p_paddr; Elf64_Xword p_filesz; Elf64_Xword p_memsz; Elf64_Xword p_align; } Elf64_Phdr; typedef __uint32_t Elf32_Word; typedef __uint32_t Elf32_Addr; typedef __uint64_t Elf32_Xword; typedef __uint32_t Elf32_Off; typedef __uint16_t Elf32_Half; typedef struct { Elf32_Word p_type; Elf32_Off p_offset; Elf32_Addr p_vaddr; Elf32_Addr p_paddr; Elf32_Word p_filesz; Elf32_Word p_memsz; Elf32_Word p_flags; Elf32_Word p_align; } Elf32_Phdr; #define PT_LOAD 1 #define PT_DYNAMIC 2 #define PT_LOOS 0x60000000 /************ ** link.h ** ************/ /* definitions according to glibc */ #ifdef _LP64 #define ElfW(type) Elf64_##type #else #define ElfW(type) Elf32_##type #endif /* _LP64 */ struct dl_phdr_info { ElfW(Addr) dlpi_addr; const char *dlpi_name; const ElfW(Phdr) *dlpi_phdr; ElfW(Half) dlpi_phnum; unsigned long long int dlpi_adds; unsigned long long int dlpi_subs; size_t dlpi_tls_modid; void *dlpi_tls_data; }; extern int dl_iterate_phdr(int (*__callback) (struct dl_phdr_info *, size_t, void *), void *__data); #endif /* _LINK_H_ */