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Diffstat (limited to 'bfd/nlm32-i386.c')
| -rw-r--r-- | bfd/nlm32-i386.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/bfd/nlm32-i386.c b/bfd/nlm32-i386.c new file mode 100644 index 0000000..20328b1 --- /dev/null +++ b/bfd/nlm32-i386.c @@ -0,0 +1,354 @@ +/* Support for 32-bit i386 NLM (NetWare Loadable Module) + Copyright (C) 1993 Free Software Foundation, Inc. + +This file is part of BFD, the Binary File Descriptor library. + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that 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, write to the Free Software +Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "bfd.h" +#include "sysdep.h" +#include "libbfd.h" + +#define ARCH_SIZE 32 +#include "libnlm.h" + +static boolean nlm_i386_read_reloc + PARAMS ((bfd *, nlmNAME(symbol_type) *, asection **, arelent *)); +static boolean nlm_i386_write_reloc + PARAMS ((bfd *, asection *, arelent *)); +static boolean nlm_i386_mangle_relocs + PARAMS ((bfd *, asection *, PTR, bfd_vma, bfd_size_type)); + +/* Adjust the reloc location by an absolute value. */ + +static reloc_howto_type nlm_i386_abs_howto = + HOWTO (0, /* type */ + 0, /* rightshift */ + 2, /* size (0 = byte, 1 = short, 2 = long) */ + 32, /* bitsize */ + false, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_bitfield, /* complain_on_overflow */ + 0, /* special_function */ + "32", /* name */ + true, /* partial_inplace */ + 0xffffffff, /* src_mask */ + 0xffffffff, /* dst_mask */ + false); /* pcrel_offset */ + +/* Adjust the reloc location by a PC relative displacement. */ + +static reloc_howto_type nlm_i386_pcrel_howto = + HOWTO (1, /* type */ + 0, /* rightshift */ + 2, /* size (0 = byte, 1 = short, 2 = long) */ + 32, /* bitsize */ + true, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_signed, /* complain_on_overflow */ + 0, /* special_function */ + "DISP32", /* name */ + true, /* partial_inplace */ + 0xffffffff, /* src_mask */ + 0xffffffff, /* dst_mask */ + true); /* pcrel_offset */ + +/* Read a NetWare i386 reloc. */ + +static boolean +nlm_i386_read_reloc (abfd, sym, secp, rel) + bfd *abfd; + nlmNAME(symbol_type) *sym; + asection **secp; + arelent *rel; +{ + bfd_byte temp[4]; + bfd_vma val; + const char *name; + + if (bfd_read (temp, sizeof (temp), 1, abfd) != sizeof (temp)) + { + bfd_error = system_call_error; + return false; + } + + val = bfd_get_32 (abfd, temp); + + /* The value is an offset into either the code or data segment. + This is the location which needs to be adjusted. + + If this is a relocation fixup rather than an imported symbol (the + sym argument is NULL) then the high bit is 0 if the location + needs to be adjusted by the address of the data segment, or 1 if + the location needs to be adjusted by the address of the code + segment. If this is an imported symbol, then the high bit is 0 + if the location is 0 if the location should be adjusted by the + offset to the symbol, or 1 if the location should adjusted by the + absolute value of the symbol. + + The second most significant bit is 0 if the value is an offset + into the data segment, or 1 if the value is an offset into the + code segment. + + All this translates fairly easily into a BFD reloc. */ + + if (sym == NULL) + { + if ((val & NLM_HIBIT) == 0) + name = NLM_INITIALIZED_DATA_NAME; + else + { + name = NLM_CODE_NAME; + val &=~ NLM_HIBIT; + } + rel->sym_ptr_ptr = bfd_get_section_by_name (abfd, name)->symbol_ptr_ptr; + rel->howto = &nlm_i386_abs_howto; + } + else + { + /* In this case we do not need to set the sym_ptr_ptr field. */ + rel->sym_ptr_ptr = NULL; + if ((val & NLM_HIBIT) == 0) + rel->howto = &nlm_i386_pcrel_howto; + else + { + rel->howto = &nlm_i386_abs_howto; + val &=~ NLM_HIBIT; + } + } + + if ((val & (NLM_HIBIT >> 1)) == 0) + *secp = bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME); + else + { + *secp = bfd_get_section_by_name (abfd, NLM_CODE_NAME); + val &=~ (NLM_HIBIT >> 1); + } + + rel->address = val; + rel->addend = 0; + + return true; +} + +/* Write a NetWare i386 reloc. */ + +static boolean +nlm_i386_write_reloc (abfd, sec, rel) + bfd *abfd; + asection *sec; + arelent *rel; +{ + asymbol *sym; + bfd_vma val; + bfd_byte temp[4]; + + /* NetWare only supports two kinds of relocs. We should check + special_function here, as well, but at the moment coff-i386 + relocs uses a special_function which does not affect what we do + here. */ + if (rel->addend != 0 + || rel->howto == NULL + || rel->howto->rightshift != 0 + || rel->howto->size != 2 + || rel->howto->bitsize != 32 + || rel->howto->bitpos != 0 + || ! rel->howto->partial_inplace + || rel->howto->src_mask != 0xffffffff + || rel->howto->dst_mask != 0xffffffff) + { + bfd_error = invalid_operation; + return false; + } + + sym = *rel->sym_ptr_ptr; + + /* The value we write out is the offset into the appropriate + segment. This offset is the section vma, adjusted by the vma of + the lowest section in that segment, plus the address of the + relocation. */ + val = bfd_get_section_vma (abfd, sec) + rel->address; + + /* The second most significant bit is 0 if the value is an offset + into the data segment, or 1 if the value is an offset into the + code segment. */ + if (bfd_get_section_flags (abfd, sec) & SEC_CODE) + { + val -= nlm_get_text_low (abfd); + val |= NLM_HIBIT >> 1; + } + else + val -= nlm_get_data_low (abfd); + + if (bfd_get_section (sym) != &bfd_und_section) + { + /* NetWare only supports absolute internal relocs. */ + if (rel->howto->pc_relative) + { + bfd_error = invalid_operation; + return false; + } + + /* The high bit is 1 if the reloc is against the code section, 0 + if against the data section. */ + if (bfd_get_section_flags (abfd, bfd_get_section (sym)) & SEC_CODE) + val |= NLM_HIBIT; + } + else + { + /* The high bit is 1 if this is an absolute reloc, 0 if it is PC + relative. */ + if (! rel->howto->pc_relative) + val |= NLM_HIBIT; + else + { + /* PC relative relocs on NetWare must be pcrel_offset. */ + if (! rel->howto->pcrel_offset) + { + bfd_error = invalid_operation; + return false; + } + } + } + + bfd_put_32 (abfd, val, temp); + if (bfd_write (temp, sizeof (temp), 1, abfd) != sizeof (temp)) + { + bfd_error = system_call_error; + return false; + } + + return true; +} + +/* I want to be able to use objcopy to turn a i386 a.out or COFF file + into a NetWare i386 module. That means that the relocs from the + source file have to be mapped into relocs that apply to the target + file. This function is called by nlm_set_section_contents to give + it a chance to rework the relocs. + + This is actually a fairly general concept. However, this is not a + general implementation. */ + +static boolean +nlm_i386_mangle_relocs (abfd, sec, data, offset, count) + bfd *abfd; + asection *sec; + PTR data; + bfd_vma offset; + bfd_size_type count; +{ + arelent **rel_ptr_ptr, **rel_end; + + rel_ptr_ptr = sec->orelocation; + rel_end = rel_ptr_ptr + sec->reloc_count; + for (; rel_ptr_ptr < rel_end; rel_ptr_ptr++) + { + arelent *rel; + asymbol *sym; + bfd_vma addend; + + rel = *rel_ptr_ptr; + sym = *rel->sym_ptr_ptr; + + /* Note that no serious harm will ensue if we fail to change a + reloc. We will wind up failing in nlm_i386_write_reloc. */ + + /* Make sure this reloc is within the data we have. We only 4 + byte relocs here, so we insist on having 4 bytes. */ + if (rel->address < offset + || rel->address + 4 > offset + count) + continue; + + /* NetWare doesn't support reloc addends, so we get rid of them + here by simply adding them into the object data. We handle + the symbol value, if any, the same way. */ + addend = rel->addend + sym->value; + + /* The value of a symbol is the offset into the section. If the + symbol is in the .bss segment, we need to include the size of + the data segment in the offset as well. Fortunately, we know + that at this point the size of the data section is in the NLM + header. */ + if (((bfd_get_section_flags (abfd, bfd_get_section (sym)) + & (SEC_CODE | SEC_DATA)) == 0) + && ((bfd_get_section_flags (abfd, bfd_get_section (sym)) + & SEC_ALLOC) != 0)) + addend += nlm_fixed_header (abfd)->dataImageSize; + + if (addend != 0 + && rel->howto != NULL + && rel->howto->rightshift == 0 + && rel->howto->size == 2 + && rel->howto->bitsize == 32 + && rel->howto->bitpos == 0 + && rel->howto->partial_inplace + && rel->howto->src_mask == 0xffffffff + && rel->howto->dst_mask == 0xffffffff) + { + bfd_vma val; + + val = bfd_get_32 (abfd, (char *) data + rel->address - offset); + val += addend; + bfd_put_32 (abfd, val, (char *) data + rel->address - offset); + rel->addend = 0; + } + + /* NetWare uses a reloc with pcrel_offset set. We adjust + pc_relative relocs accordingly. We are going to change the + howto field, so we can only do this if the current one is + compatible. We should check special_function here, but at + the moment coff-i386 uses a special_function which does not + affect what we are doing here. */ + if (rel->howto != NULL + && rel->howto->pc_relative + && ! rel->howto->pcrel_offset + && rel->howto->rightshift == 0 + && rel->howto->size == 2 + && rel->howto->bitsize == 32 + && rel->howto->bitpos == 0 + && rel->howto->partial_inplace + && rel->howto->src_mask == 0xffffffff + && rel->howto->dst_mask == 0xffffffff) + { + bfd_vma val; + + /* When pcrel_offset is not set, it means that the negative + of the address of the memory location is stored in the + memory location. We must add it back in. */ + val = bfd_get_32 (abfd, (char *) data + rel->address - offset); + val += rel->address; + bfd_put_32 (abfd, val, (char *) data + rel->address - offset); + + rel->howto = &nlm_i386_pcrel_howto; + } + } + + return true; +} + +static const struct nlm_backend_data nlm32_i386_backend = +{ + bfd_arch_i386, + nlm_i386_read_reloc, + nlm_i386_write_reloc, + nlm_i386_mangle_relocs +}; + +#define TARGET_LITTLE_NAME "nlm32-i386" +#define TARGET_LITTLE_SYM nlmNAME(i386_vec) +#define TARGET_BACKEND_DATA &nlm32_i386_backend + +#include "nlm-target.h" |