/**************************************************************************** * arch/arm/src/armv-7a/arm_elf.c * * Copyright (C) 2013-2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "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 * COPYRIGHT OWNER OR CONTRIBUTORS 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: up_checkarch * * Description: * Given the ELF header in 'hdr', verify that the ELF file is appropriate * for the current, configured architecture. Every architecture that uses * the ELF loader must provide this function. * * Input Parameters: * hdr - The ELF header read from the ELF file. * * Returned Value: * True if the architecture supports this ELF file. * ****************************************************************************/ bool up_checkarch(FAR const Elf32_Ehdr *ehdr) { /* Make sure it's an ARM executable */ if (ehdr->e_machine != EM_ARM) { bdbg("Not for ARM: e_machine=%04x\n", ehdr->e_machine); return -ENOEXEC; } /* Make sure that 32-bit objects are supported */ if (ehdr->e_ident[EI_CLASS] != ELFCLASS32) { bdbg("Need 32-bit objects: e_ident[EI_CLASS]=%02x\n", ehdr->e_ident[EI_CLASS]); return -ENOEXEC; } /* Verify endian-ness */ #ifdef CONFIG_ENDIAN_BIG if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) #else if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) #endif { bdbg("Wrong endian-ness: e_ident[EI_DATA]=%02x\n", ehdr->e_ident[EI_DATA]); return -ENOEXEC; } /* Make sure the entry point address is properly aligned */ if ((ehdr->e_entry & 3) != 0) { bdbg("Entry point is not properly aligned: %08x\n", ehdr->e_entry); return -ENOEXEC; } /* TODO: Check ABI here. */ return OK; } /**************************************************************************** * Name: up_relocate and up_relocateadd * * Description: * Perform on architecture-specific ELF relocation. Every architecture * that uses the ELF loader must provide this function. * * Input Parameters: * rel - The relocation type * sym - The ELF symbol structure containing the fully resolved value. * There are a few relocation types for a few architectures that do * not require symbol information. For those, this value will be * NULL. Implementations of these functions must be able to handle * that case. * addr - The address that requires the relocation. * * Returned Value: * Zero (OK) if the relocation was successful. Otherwise, a negated errno * value indicating the cause of the relocation failure. * ****************************************************************************/ int up_relocate(FAR const Elf32_Rel *rel, FAR const Elf32_Sym *sym, uintptr_t addr) { int32_t offset; unsigned int relotype; /* All relocations except R_ARM_V4BX depend upon having valid symbol * information. */ relotype = ELF32_R_TYPE(rel->r_info); if (sym == NULL && relotype != R_ARM_NONE && relotype != R_ARM_V4BX) { return -EINVAL; } /* Handle the relocation by relocation type */ switch (relotype) { case R_ARM_NONE: { /* No relocation */ } break; case R_ARM_PC24: case R_ARM_CALL: case R_ARM_JUMP24: { bvdbg("Performing PC24 [%d] link at addr %08lx [%08lx] to sym '%s' st_value=%08lx\n", ELF32_R_TYPE(rel->r_info), (long)addr, (long)(*(uint32_t*)addr), sym, (long)sym->st_value); offset = (*(uint32_t*)addr & 0x00ffffff) << 2; if (offset & 0x02000000) { offset -= 0x04000000; } offset += sym->st_value - addr; if (offset & 3 || offset <= (int32_t) 0xfe000000 || offset >= (int32_t) 0x02000000) { bdbg(" ERROR: PC24 [%d] relocation out of range, offset=%08lx\n", ELF32_R_TYPE(rel->r_info), offset); return -EINVAL; } offset >>= 2; *(uint32_t*)addr &= 0xff000000; *(uint32_t*)addr |= offset & 0x00ffffff; } break; case R_ARM_ABS32: case R_ARM_TARGET1: /* New ABI: TARGET1 always treated as ABS32 */ { bvdbg("Performing ABS32 link at addr=%08lx [%08lx] to sym=%p st_value=%08lx\n", (long)addr, (long)(*(uint32_t*)addr), sym, (long)sym->st_value); *(uint32_t*)addr += sym->st_value; } break; case R_ARM_V4BX: { bvdbg("Performing V4BX link at addr=%08lx [%08lx]\n", (long)addr, (long)(*(uint32_t*)addr)); /* Preserve only Rm and the condition code */ *(uint32_t*)addr &= 0xf000000f; /* Change instruction to 'mov pc, Rm' */ *(uint32_t*)addr |= 0x01a0f000; } break; case R_ARM_PREL31: { bvdbg("Performing PREL31 link at addr=%08lx [%08lx] to sym=%p st_value=%08lx\n", (long)addr, (long)(*(uint32_t*)addr), sym, (long)sym->st_value); offset = *(uint32_t*)addr + sym->st_value - addr; *(uint32_t*)addr = offset & 0x7fffffff; } break; case R_ARM_MOVW_ABS_NC: case R_ARM_MOVT_ABS: { bvdbg("Performing MOVx_ABS [%d] link at addr=%08lx [%08lx] to sym=%p st_value=%08lx\n", ELF32_R_TYPE(rel->r_info), (long)addr, (long)(*(uint32_t*)addr), sym, (long)sym->st_value); offset = *(uint32_t*)addr; offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); offset = (offset ^ 0x8000) - 0x8000; offset += sym->st_value; if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) { offset >>= 16; } *(uint32_t*)addr &= 0xfff0f000; *(uint32_t*)addr |= ((offset & 0xf000) << 4) | (offset & 0x0fff); } break; default: bdbg("Unsupported relocation: %d\n", ELF32_R_TYPE(rel->r_info)); return -EINVAL; } return OK; } int up_relocateadd(FAR const Elf32_Rela *rel, FAR const Elf32_Sym *sym, uintptr_t addr) { bdbg("RELA relocation not supported\n"); return -ENOSYS; }