diff options
| -rw-r--r-- | gold/ChangeLog | 33 | ||||
| -rw-r--r-- | gold/script-sections.cc | 423 | ||||
| -rw-r--r-- | gold/script-sections.h | 12 | ||||
| -rw-r--r-- | gold/testsuite/memory_test.s | 10 | ||||
| -rwxr-xr-x | gold/testsuite/memory_test.sh | 19 | ||||
| -rw-r--r-- | gold/testsuite/memory_test.t | 8 | ||||
| -rw-r--r-- | ld/ChangeLog | 5 | ||||
| -rw-r--r-- | ld/ld.texinfo | 110 | ||||
| -rw-r--r-- | ld/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | ld/testsuite/ld-scripts/rgn-at5.d | 11 | ||||
| -rw-r--r-- | ld/testsuite/ld-scripts/rgn-at5.t | 10 |
11 files changed, 496 insertions, 150 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index 03c5fc3..07ee753 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,36 @@ +2010-10-06 Nick Clifton <nickc@redhat.com> + + * script-sections.cc(class Memory_region): Remove + current_lma_offset_ field. Rename current_vma_offset_ to + current_offset_. Add last_section_ field. + (Memory_region::get_current_vma_address): Rename to + get_current_address. + (Memory_region::get_current_lma_address): Delete. + (Memory_region::increment_vma_offset): Rename to + increment_offset. + (Memory_region::increment_lma_offset): Delete. + (Memory_region::attributes_compatible): New method. Returns + true if the provided section is compatible with the region. + (Memory_region::get_last_section): New method. Returns the last + section to use the region. + (Memory_region::set_last_section): New method. Stores the last + section to use the region. + (Script_sections::block_in_region): New method. Returns true if + a block of memory is contained within a region. + (Script_sections::find_memory_region): New method. Locates a + memory region to be used to set a VMA or LMA address. + (Output_section_definition::set_section_addresses): Add code to + check for addresses set by memory regions. + (Output_segment::set_section_addresses): Remove memory region + walking code. + (Script_sections::create_segment): Add a warning if a header + segment is created outside of any region. + * script-sections.h (class Script_sections): Add prototypes for + find_memory_region and block_in_region methods. + * testsuite/memory_test.s: Use .long instead of .word. + * testsuite/memory_test.t: Add some more output sections. + * testsuite/memory_test.sh: Update expected output. + 2010-10-02 Doug Kwan <dougkwan@google.com> * symtab.cc (Symbol_table::Symbol_table_hash::operator()): Move diff --git a/gold/script-sections.cc b/gold/script-sections.cc index 2de3a3f..550a6a3 100644 --- a/gold/script-sections.cc +++ b/gold/script-sections.cc @@ -53,10 +53,10 @@ class Memory_region attributes_(attributes), start_(start), length_(length), - current_vma_offset_(0), - current_lma_offset_(0), + current_offset_(0), vma_sections_(), - lma_sections_() + lma_sections_(), + last_section_(NULL) { } // Return the name of this region. @@ -87,45 +87,40 @@ class Memory_region } Expression* - get_current_vma_address(void) const + get_current_address() const { return script_exp_binary_add(this->start_, - script_exp_integer(this->current_vma_offset_)); - } - - Expression* - get_current_lma_address(void) const - { - return - script_exp_binary_add(this->start_, - script_exp_integer(this->current_lma_offset_)); + script_exp_integer(this->current_offset_)); } void - increment_vma_offset(std::string section_name, uint64_t amount, - const Symbol_table* symtab, const Layout* layout) + increment_offset(std::string section_name, uint64_t amount, + const Symbol_table* symtab, const Layout* layout) { - this->current_vma_offset_ += amount; + this->current_offset_ += amount; - if (this->current_vma_offset_ + if (this->current_offset_ > this->length_->eval(symtab, layout, false)) - gold_error (_("section %s overflows end of region %s"), - section_name.c_str(), this->name_.c_str()); + gold_error(_("section %s overflows end of region %s"), + section_name.c_str(), this->name_.c_str()); } - void - increment_lma_offset(std::string section_name, uint64_t amount, - const Symbol_table* symtab, const Layout* layout) + // Returns true iff there is room left in this region + // for AMOUNT more bytes of data. + bool + has_room_for(const Symbol_table* symtab, const Layout* layout, + uint64_t amount) const { - this->current_lma_offset_ += amount; - - if (this->current_lma_offset_ - > this->length_->eval(symtab, layout, false)) - gold_error (_("section %s overflows end of region %s (based on load address)"), - section_name.c_str(), this->name_.c_str()); + return (this->current_offset_ + amount + < this->length_->eval(symtab, layout, false)); } + // Return true if the provided section flags + // are compatible with this region's attributes. + bool + attributes_compatible(elfcpp::Elf_Xword flags, elfcpp::Elf_Xword type) const; + void add_section(Output_section_definition* sec, bool vma) { @@ -140,41 +135,103 @@ class Memory_region // Return the start of the list of sections // whose VMAs are taken from this region. Section_list::const_iterator - get_vma_section_list_start(void) const + get_vma_section_list_start() const { return this->vma_sections_.begin(); } // Return the start of the list of sections // whose LMAs are taken from this region. Section_list::const_iterator - get_lma_section_list_start(void) const + get_lma_section_list_start() const { return this->lma_sections_.begin(); } // Return the end of the list of sections // whose VMAs are taken from this region. Section_list::const_iterator - get_vma_section_list_end(void) const + get_vma_section_list_end() const { return this->vma_sections_.end(); } // Return the end of the list of sections // whose LMAs are taken from this region. Section_list::const_iterator - get_lma_section_list_end(void) const + get_lma_section_list_end() const { return this->lma_sections_.end(); } + Output_section_definition* + get_last_section() const + { return this->last_section_; } + + void + set_last_section(Output_section_definition* sec) + { this->last_section_ = sec; } + private: std::string name_; unsigned int attributes_; Expression* start_; Expression* length_; - uint64_t current_vma_offset_; - uint64_t current_lma_offset_; + // The offset to the next free byte in the region. + // Note - for compatibility with GNU LD we only maintain one offset + // regardless of whether the region is being used for VMA values, + // LMA values, or both. + uint64_t current_offset_; // A list of sections whose VMAs are set inside this region. Section_list vma_sections_; // A list of sections whose LMAs are set inside this region. Section_list lma_sections_; + // The latest section to make use of this region. + Output_section_definition* last_section_; }; +// Return true if the provided section flags +// are compatible with this region's attributes. + +bool +Memory_region::attributes_compatible(elfcpp::Elf_Xword flags, + elfcpp::Elf_Xword type) const +{ + unsigned int attrs = this->attributes_; + + // No attributes means that this region is not compatible with anything. + if (attrs == 0) + return false; + + bool match = true; + do + { + switch (attrs & - attrs) + { + case MEM_EXECUTABLE: + if ((flags & elfcpp::SHF_EXECINSTR) == 0) + match = false; + break; + + case MEM_WRITEABLE: + if ((flags & elfcpp::SHF_WRITE) == 0) + match = false; + break; + + case MEM_READABLE: + // All sections are presumed readable. + break; + + case MEM_ALLOCATABLE: + if ((flags & elfcpp::SHF_ALLOC) == 0) + match = false; + break; + + case MEM_INITIALIZED: + if ((type & elfcpp::SHT_NOBITS) != 0) + match = false; + break; + } + attrs &= ~ (attrs & - attrs); + } + while (attrs != 0); + + return match; +} + // Print a memory region. void @@ -1512,7 +1569,7 @@ Output_section_element_input::set_section_addresses( isi.set_section_name(relobj->section_name(shndx)); if (p->is_relaxed_input_section()) { - // We use current data size because relxed section sizes may not + // We use current data size because relaxed section sizes may not // have finalized yet. isi.set_size(p->relaxed_input_section()->current_data_size()); isi.set_addralign(p->relaxed_input_section()->addralign()); @@ -1857,8 +1914,8 @@ class Output_section_definition : public Sections_element set_section_lma(Expression* address) { this->load_address_ = address; } - std::string - get_section_name(void) const + const std::string& + get_section_name() const { return this->name_; } private: @@ -2098,6 +2155,107 @@ Output_section_definition::output_section_name( return NULL; } +// Return true if memory from START to START + LENGTH is contained +// within a memory region. + +bool +Script_sections::block_in_region(Symbol_table* symtab, Layout* layout, + uint64_t start, uint64_t length) const +{ + if (this->memory_regions_ == NULL) + return false; + + for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); + mr != this->memory_regions_->end(); + ++mr) + { + uint64_t s = (*mr)->start_address()->eval(symtab, layout, false); + uint64_t l = (*mr)->length()->eval(symtab, layout, false); + + if (s <= start + && (s + l) >= (start + length)) + return true; + } + + return false; +} + +// Find a memory region that should be used by a given output SECTION. +// If provided set PREVIOUS_SECTION_RETURN to point to the last section +// that used the return memory region. + +Memory_region* +Script_sections::find_memory_region( + Output_section_definition* section, + bool find_vma_region, + Output_section_definition** previous_section_return) +{ + if (previous_section_return != NULL) + * previous_section_return = NULL; + + // Walk the memory regions specified in this script, if any. + if (this->memory_regions_ == NULL) + return NULL; + + // The /DISCARD/ section never gets assigned to any region. + if (section->get_section_name() == "/DISCARD/") + return NULL; + + Memory_region* first_match = NULL; + + // First check to see if a region has been assigned to this section. + for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); + mr != this->memory_regions_->end(); + ++mr) + { + if (find_vma_region) + { + for (Memory_region::Section_list::const_iterator s = + (*mr)->get_vma_section_list_start(); + s != (*mr)->get_vma_section_list_end(); + ++s) + if ((*s) == section) + { + (*mr)->set_last_section(section); + return *mr; + } + } + else + { + for (Memory_region::Section_list::const_iterator s = + (*mr)->get_lma_section_list_start(); + s != (*mr)->get_lma_section_list_end(); + ++s) + if ((*s) == section) + { + (*mr)->set_last_section(section); + return *mr; + } + } + + // Make a note of the first memory region whose attributes + // are compatible with the section. If we do not find an + // explicit region assignment, then we will return this region. + Output_section* out_sec = section->get_output_section(); + if (first_match == NULL + && (*mr)->attributes_compatible(out_sec->flags(), + out_sec->type())) + first_match = *mr; + } + + // With LMA computations, if an explicit region has not been specified then + // we will want to set the difference between the VMA and the LMA of the + // section were searching for to be the same as the difference between the + // VMA and LMA of the last section to be added to first matched region. + // Hence, if it was asked for, we return a pointer to the last section + // known to be used by the first matched region. + if (first_match != NULL + && previous_section_return != NULL) + *previous_section_return = first_match->get_last_section(); + + return first_match; +} + // Set the section address. Note that the OUTPUT_SECTION_ field will // be NULL if no input sections were mapped to this output section. // We still have to adjust dot and process symbol assignments. @@ -2109,28 +2267,42 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, uint64_t* dot_alignment, uint64_t* load_address) { + Memory_region* vma_region = NULL; + Memory_region* lma_region = NULL; + Script_sections* script_sections = + layout->script_options()->script_sections(); uint64_t address; uint64_t old_dot_value = *dot_value; uint64_t old_load_address = *load_address; - // Check for --section-start. - bool is_address_set = false; - if (this->output_section_ != NULL) - is_address_set = - parameters->options().section_start(this->output_section_->name(), - &address); - if (!is_address_set) + // Decide the start address for the section. The algorithm is: + // 1) If an address has been specified in a linker script, use that. + // 2) Otherwise if a memory region has been specified for the section, + // use the next free address in the region. + // 3) Otherwise if memory regions have been specified find the first + // region whose attributes are compatible with this section and + // install it into that region. + // 4) Otherwise use the current location counter. + + if (this->output_section_ != NULL + // Check for --section-start. + && parameters->options().section_start(this->output_section_->name(), + &address)) + ; + else if (this->address_ == NULL) { - if (this->address_ == NULL) - address = *dot_value; + vma_region = script_sections->find_memory_region(this, true, NULL); + + if (vma_region != NULL) + address = vma_region->get_current_address()->eval(symtab, layout, + false); else - { - address = this->address_->eval_with_dot(symtab, layout, true, - *dot_value, NULL, NULL, - dot_alignment); - } + address = *dot_value; } - + else + address = this->address_->eval_with_dot(symtab, layout, true, + *dot_value, NULL, NULL, + dot_alignment); uint64_t align; if (this->align_ == NULL) { @@ -2167,18 +2339,74 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, this->evaluated_address_ = address; this->evaluated_addralign_ = align; + uint64_t laddr; + if (this->load_address_ == NULL) - this->evaluated_load_address_ = address; + { + Output_section_definition* previous_section; + + // Determine if an LMA region has been set for this section. + lma_region = script_sections->find_memory_region(this, false, + &previous_section); + + if (lma_region != NULL) + { + if (previous_section == NULL) + // The LMA address was explicitly set to the given region. + laddr = lma_region->get_current_address()->eval(symtab, layout, + false); + else + { + // We are not going to use the discovered lma_region, so + // make sure that we do not update it in the code below. + lma_region = NULL; + + if (this->address_ != NULL || previous_section == this) + { + // Either an explicit VMA address has been set, or an + // explicit VMA region has been set, so set the LMA equal to + // the VMA. + laddr = address; + } + else + { + // The LMA address was not explicitly or implicitly set. + // + // We have been given the first memory region that is + // compatible with the current section and a pointer to the + // last section to use this region. Set the LMA of this + // section so that the difference between its' VMA and LMA + // is the same as the difference between the VMA and LMA of + // the last section in the given region. + laddr = address + (previous_section->evaluated_load_address_ + - previous_section->evaluated_address_); + } + } + + if (this->output_section_ != NULL) + this->output_section_->set_load_address(laddr); + } + else + { + // Do not set the load address of the output section, if one exists. + // This allows future sections to determine what the load address + // should be. If none is ever set, it will default to being the + // same as the vma address. + laddr = address; + } + } else { - uint64_t laddr = - this->load_address_->eval_with_dot(symtab, layout, true, *dot_value, - this->output_section_, NULL, NULL); + laddr = this->load_address_->eval_with_dot(symtab, layout, true, + *dot_value, + this->output_section_, + NULL, NULL); if (this->output_section_ != NULL) this->output_section_->set_load_address(laddr); - this->evaluated_load_address_ = laddr; } + this->evaluated_load_address_ = laddr; + uint64_t subalign; if (this->subalign_ == NULL) subalign = 0; @@ -2233,8 +2461,38 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, gold_assert(input_sections.empty()); - if (this->load_address_ == NULL || this->output_section_ == NULL) + if (vma_region != NULL) + { + // Update the VMA region being used by the section now that we know how + // big it is. Use the current address in the region, rather than + // start_address because that might have been aligned upwards and we + // need to allow for the padding. + Expression* addr = vma_region->get_current_address(); + uint64_t size = *dot_value - addr->eval(symtab, layout, false); + + vma_region->increment_offset(this->get_section_name(), size, + symtab, layout); + } + + // If the LMA region is different from the VMA region, then increment the + // offset there as well. Note that we use the same "dot_value - + // start_address" formula that is used in the load_address assignment below. + if (lma_region != NULL && lma_region != vma_region) + lma_region->increment_offset(this->get_section_name(), + *dot_value - start_address, + symtab, layout); + + // Compute the load address for the following section. + if (this->output_section_ == NULL) *load_address = *dot_value; + else if (this->load_address_ == NULL) + { + if (lma_region == NULL) + *load_address = *dot_value; + else + *load_address = + lma_region->get_current_address()->eval(symtab, layout, false); + } else *load_address = (this->output_section_->load_address() + (*dot_value - start_address)); @@ -2779,7 +3037,7 @@ Script_sections::add_memory_region(const char* name, size_t namelen, this->memory_regions_ = new Memory_regions(); else if (this->find_memory_region(name, namelen)) { - gold_error (_("region '%.*s' already defined"), static_cast<int>(namelen), + gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen), name); // FIXME: Add a GOLD extension to allow multiple regions with the same // name. This would amount to a single region covering disjoint blocks @@ -3178,41 +3436,6 @@ Output_segment* Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout) { gold_assert(this->saw_sections_clause_); - - // Walk the memory regions specified in this script, if any. - if (this->memory_regions_ != NULL) - { - for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); - mr != this->memory_regions_->end(); - ++mr) - { - // FIXME: What should we do with the attributes of the regions ? - - // For each region, set the VMA of the sections associated with it. - for (Memory_region::Section_list::const_iterator s = - (*mr)->get_vma_section_list_start(); - s != (*mr)->get_vma_section_list_end(); - ++s) - { - (*s)->set_section_vma((*mr)->get_current_vma_address()); - (*mr)->increment_vma_offset((*s)->get_section_name(), - (*s)->get_output_section()->current_data_size(), - symtab, layout); - } - - // Similarly, set the LMA values. - for (Memory_region::Section_list::const_iterator s = - (*mr)->get_lma_section_list_start(); - s != (*mr)->get_lma_section_list_end(); - ++s) - { - (*s)->set_section_lma((*mr)->get_current_lma_address()); - (*mr)->increment_lma_offset((*s)->get_section_name(), - (*s)->get_output_section()->current_data_size(), - symtab, layout); - } - } - } // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain // for our representation. @@ -3567,6 +3790,18 @@ Script_sections::create_segments(Layout* layout, uint64_t dot_alignment) if (lma < subtract || vma < subtract) return NULL; + // If memory regions have been specified and the address range + // we are about to use is not contained within any region then + // issue a warning message about the segment we are going to + // create. It will be outside of any region and so possibly + // using non-existent or protected memory. We test LMA rather + // than VMA since we assume that the headers will never be + // relocated. + if (this->memory_regions_ != NULL + && !this->block_in_region (NULL, layout, lma - subtract, subtract)) + gold_warning(_("creating a segment to contain the file and program" + " headers outside of any MEMORY region")); + Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD, elfcpp::PF_R); load_seg->set_addresses(vma - subtract, lma - subtract); diff --git a/gold/script-sections.h b/gold/script-sections.h index 1a0b760..ee1adae 100644 --- a/gold/script-sections.h +++ b/gold/script-sections.h @@ -234,10 +234,20 @@ class Script_sections Expression* find_memory_region_length(const char*, size_t); - // Find a memory region. + // Find a memory region by name. Memory_region* find_memory_region(const char*, size_t); + // Find a memory region that should be used by a given output section. + Memory_region* + find_memory_region(Output_section_definition*, bool, + Output_section_definition**); + + // Returns true if the provide block of memory is contained + // within a memory region. + bool + block_in_region(Symbol_table*, Layout*, uint64_t, uint64_t) const; + // Set the memory region of the section. void set_memory_region(Memory_region*, bool); diff --git a/gold/testsuite/memory_test.s b/gold/testsuite/memory_test.s index dbb63ea..ce8576c 100644 --- a/gold/testsuite/memory_test.s +++ b/gold/testsuite/memory_test.s @@ -1,14 +1,14 @@ .section .sec0, "a" - .word 0 + .long 0 .section .sec1, "a" - .word 0x11 + .long 0x11 .section .sec2, "a" - .word 0x22 + .long 0x22 .section .sec3, "a" - .word 0x33 + .long 0x33 .section .sec4, "a" - .word 0x44 + .long 0x44 diff --git a/gold/testsuite/memory_test.sh b/gold/testsuite/memory_test.sh index 5c172f4..db3917a 100755 --- a/gold/testsuite/memory_test.sh +++ b/gold/testsuite/memory_test.sh @@ -23,6 +23,14 @@ # MA 02110-1301, USA. +# NOTE: The linker script used in this test (memory_test.t) +# should be the same as the one used in the rgn-at5 linker +# test (ld/testsuite/ld-scripts/rgn-at5.t). +# +# Modulo some section ordering the output from GOLD in this +# test should be the same as the output from GNU LD in the +# rgn-at5 test. + check() { file=$1 @@ -36,13 +44,14 @@ check() } check memory_test.stdout \ - " LOAD 0x001000 0x0*00000000 0x0*00000000 0x00000\?2 0x00000\?2 R 0x1000" + " LOAD 0x001000 0x0*02000 0x0*02000 0x0*04 0x0*04 R 0x1000" check memory_test.stdout \ - " LOAD 0x00112c 0x0*00001000 0x0*0000012c 0x00000\?2 0x00000\?2 R 0x1000" + " LOAD 0x001004 0x0*01000 0x0*02004 0x0*04 0x0*04 R 0x1000" check memory_test.stdout \ - " LOAD 0x002000 0x0*00005000 0x0*00005000 0x00000\?2 0x00000\?2 R 0x1000" + " LOAD 0x001008 0x0*02008 0x0*02008 0x0*08 0x0*08 R 0x1000" check memory_test.stdout \ - " LOAD 0x00203c 0x0*00004000 0x0*0000603c 0x00000\?2 0x00000\?2 R 0x1000" - + " LOAD 0x002000 0x0*05000 0x0*05000 0x0*04 0x0*04 R 0x1000" +check memory_test.stdout \ + " LOAD 0x00203c 0x0*04000 0x0*0603c 0x0*04 0x0*04 R 0x1000" exit 0 diff --git a/gold/testsuite/memory_test.t b/gold/testsuite/memory_test.t index 5963c93..3a35994 100644 --- a/gold/testsuite/memory_test.t +++ b/gold/testsuite/memory_test.t @@ -10,13 +10,17 @@ SECTIONS { .sec0 : { *(*.sec0) } - .sec1 ORIGIN (region1) : AT(LENGTH (region2)) { *(*.sec1) } + .sec1 ORIGIN (region1) : { *(*.sec1) } AT> region2 - fred = ORIGIN (region1) + LENGTH (region1) ; + fred = ORIGIN (region1) + LENGTH (region1); .sec2 : { *(*.sec2) } > region3 AT> region4 .sec3 0x5000 : { *(*.sec3) } + .sec4 : { *(*.sec4) } AT> region2 + + .sec5 : { LONG(0x5555) } > region2 + /DISCARD/ : { *(*) } } diff --git a/ld/ChangeLog b/ld/ChangeLog index b1b0ef6..24f3bc8 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,8 @@ +2010-10-06 Nick Clifton <nickc@redhat.com> + + * ld.texinfo: Update description of computation of VMA and LMA + addresses for output sections. + 2010-10-06 Ralf Wildenhues <Ralf.Wildenhues@gmx.de> * Makefile.am (ALL_64_EMULATIONS): Fix typo in last commit. diff --git a/ld/ld.texinfo b/ld/ld.texinfo index 206068a..36e2460 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -3682,33 +3682,55 @@ Discarding}. @cindex address, section @cindex section address The @var{address} is an expression for the VMA (the virtual memory -address) of the output section. If you do not provide @var{address}, -the linker will set it based on @var{region} if present, or otherwise -based on the current value of the location counter. - -If you provide @var{address}, the address of the output section will be -set to precisely that. If you provide neither @var{address} nor -@var{region}, then the address of the output section will be set to the -current value of the location counter aligned to the alignment -requirements of the output section. The alignment requirement of the -output section is the strictest alignment of any input section contained -within the output section. - -For example, +address) of the output section. This address is optional, but if it +is provided then the output address will be set exactly as specified. + +If the output address is not specified then one will be chosen for the +section, based on the heuristic below. This address will be adjusted +to fit the alignment requirement of the output section. The +alignment requirement is the strictest alignment of any input section +contained within the output section. + +The output section address heuristic is as follows: + +@itemize @bullet +@item +If an output memory @var{region} is set for the section then it +is added to this region and its address will be the next free address +in that region. + +@item +If the MEMORY command has been used to create a list of memory +regions then the first region which has attributes compatible with the +section is selected to contain it. The section's output address will +be the next free address in that region; @ref{MEMORY}. + +@item +If no memory regions were specified, or none match the section then +the output address will be based on the current value of the location +counter. +@end itemize + +@noindent +For example: + @smallexample .text . : @{ *(.text) @} @end smallexample + @noindent and + @smallexample .text : @{ *(.text) @} @end smallexample + @noindent are subtly different. The first will set the address of the @samp{.text} output section to the current value of the location counter. The second will set it to the current value of the location -counter aligned to the strictest alignment of a @samp{.text} input -section. +counter aligned to the strictest alignment of any of the @samp{.text} +input sections. The @var{address} may be an arbitrary expression; @ref{Expressions}. For example, if you want to align the section on a 0x10 byte boundary, @@ -4307,25 +4329,44 @@ SECTIONS @{ @cindex load address @cindex section load address Every section has a virtual address (VMA) and a load address (LMA); see -@ref{Basic Script Concepts}. The address expression which may appear in -an output section description sets the VMA (@pxref{Output Section -Address}). +@ref{Basic Script Concepts}. The virtual address is specified by the +@pxref{Output Section Address} described earlier. The load address is +specified by the @code{AT} or @code{AT>} keywords. Specifying a load +address is optional. -The expression @var{lma} that follows the @code{AT} keyword specifies -the load address of the section. - -Alternatively, with @samp{AT>@var{lma_region}} expression, you may -specify a memory region for the section's load address. @xref{MEMORY}. -Note that if the section has not had a VMA assigned to it then the -linker will use the @var{lma_region} as the VMA region as well. +The @code{AT} keyword takes an expression as an argument. This +specifies the exact load address of the section. The @code{AT>} keyword +takes the name of a memory region as an argument. @xref{MEMORY}. The +load address of the section is set to the next free address in the +region, aligned to the section's alignment requirements. If neither @code{AT} nor @code{AT>} is specified for an allocatable -section, the linker will set the LMA such that the difference between -VMA and LMA for the section is the same as the preceding output -section in the same region. If there is no preceding output section -or the section is not allocatable, the linker will set the LMA equal -to the VMA. -@xref{Output Section Region}. +section, the linker will use the following heuristic to determine the +load address: + +@itemize @bullet +@item +If the section has a specific VMA address, then this is used as +the LMA address as well. + +@item +If the section is not allocatable then its LMA is set to its VMA. + +@item +Otherwise if a memory region can be found that is compatible +with the current section, and this region contains at least one +section, then the LMA is set so the difference between the +VMA and LMA is the same as the difference between the VMA and LMA of +the last section in the located region. + +@item +If no memory regions have been declared then a default region +that covers the entire address space is used in the previous step. + +@item +If no suitable region could be found, or there was no previous +section then the LMA is set equal to the VMA. +@end itemize @cindex ROM initialized data @cindex initialized data in ROM @@ -4364,12 +4405,11 @@ extern char _etext, _data, _edata, _bstart, _bend; char *src = &_etext; char *dst = &_data; -/* ROM has data at end of text; copy it. */ -while (dst < &_edata) @{ +/* ROM has data at end of text; copy it. */ +while (dst < &_edata) *dst++ = *src++; -@} -/* Zero bss */ +/* Zero bss. */ for (dst = &_bstart; dst< &_bend; dst++) *dst = 0; @end group diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index 3342d62..245f7d5 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2010-10-06 Nick Clifton <nickc@redhat.com> + + * ld-scripts/rgn-at5.t: Add some more output sections. + * ld-scripts/rgn-at5.d: Update expected output. + 2010-09-30 H.J. Lu <hongjiu.lu@intel.com> PR ld/11812 diff --git a/ld/testsuite/ld-scripts/rgn-at5.d b/ld/testsuite/ld-scripts/rgn-at5.d index e33b34b..972c6c2 100644 --- a/ld/testsuite/ld-scripts/rgn-at5.d +++ b/ld/testsuite/ld-scripts/rgn-at5.d @@ -11,9 +11,10 @@ Sections: Idx +Name +Size +VMA +LMA +File off +Algn +Flags - 0 .sec0 +0+4 +0+02000 +0+2000 +0+02000 +.* - 1 .sec1 +0+4 +0+01000 +0+012c +0+01000 +.* - 2 .sec2 +0+4 +0+04000 +0+603c +0+04000 +.* - 3 .sec3 +0+4 +0+05000 +0+412c +0+03000 +.* - 4 .sec4 +0+4 +0+02004 +0+2004 +0+02004 +.* + 0 .sec0 +0+4 +0+2000 +0+2000 +0+1000 +.* + 1 .sec1 +0+4 +0+1000 +0+2004 +0+2000 +.* + 2 .sec2 +0+4 +0+4000 +0+603c +0+4000 +.* + 3 .sec3 +0+4 +0+5000 +0+5000 +0+3000 +.* + 4 .sec4 +0+4 +0+2008 +0+2008 +0+2008 +.* + 5 .sec5 +0+4 +0+200c +0+200c +0+200c +.* #pass diff --git a/ld/testsuite/ld-scripts/rgn-at5.t b/ld/testsuite/ld-scripts/rgn-at5.t index 53ad242..3a35994 100644 --- a/ld/testsuite/ld-scripts/rgn-at5.t +++ b/ld/testsuite/ld-scripts/rgn-at5.t @@ -10,13 +10,17 @@ SECTIONS { .sec0 : { *(*.sec0) } - .sec1 ORIGIN (region1) : AT(LENGTH (region2)) { *(*.sec1) } + .sec1 ORIGIN (region1) : { *(*.sec1) } AT> region2 - fred = ORIGIN (region1) + LENGTH (region1) ; + fred = ORIGIN (region1) + LENGTH (region1); .sec2 : { *(*.sec2) } > region3 AT> region4 .sec3 0x5000 : { *(*.sec3) } - /DISCARD/ : { *(.reginfo) } + .sec4 : { *(*.sec4) } AT> region2 + + .sec5 : { LONG(0x5555) } > region2 + + /DISCARD/ : { *(*) } } |