diff options
Diffstat (limited to 'ld/NEWS')
| -rw-r--r-- | ld/NEWS | 77 |
1 files changed, 4 insertions, 73 deletions
@@ -1,74 +1,5 @@ -*- text -*- -* The linker script has a new command to insert a timestamp - TIMESTAMP - inserts the current time (seconds since Epoch) as a 64-bit value - -* The linker script syntax has new commands for debugging a linker script - DEBUG ON turns on debugging - DEBUG OFF turns off debugging - -* The linker script syntax has new commands for handling CRC-32/64 calculations - on the '.text' section - It uses code from https://www.libcrc.org/ - - DIGEST "<label>[#<endian>]" "CRC32" (start, end) - DIGEST "<label>[#<endian>]" "CRC64-ECMA" (start, end) - DIGEST "<label>[#<endian>]" "CRC64-GO-ISO" (start, end) - DIGEST "<label>[#<endian>]" "CRC64-GO-ISO-R" (start, end) - DIGEST "<label>[#<endian>]" "CRC64-WE" (start, end) - DIGEST "<label>[#<endian>]" "CRC64-XZ" (start, end) - DIGEST "<label>[#<endian>]" POLY (<params>) (start, end) - DIGEST TABLE "<label>[#<endian>]" - - The CRC32, CRC64-ECMA, CRC64-ISO, CRC64-WE and POLY defines - the polynome to use and reserves space for the 32/64-bit CRC in the - current section (default ".text"). It also defines a label "<label>". - The endian can be specified through "#BE" or "#LE" modifiers for - big endian or little endian. This overrides the "-BE" or "-LE" switches on the - command line. If no specification is used, little endian - digest and table will be emitted. - The generated label does not include the modifier. - - When generating a custom polynome you have to supply parameters - in the following order - * size {32 | 64 } - * polynome - * initial initial value of crc - * xor value xor with this before returning result - * input reflect bitreverse input data - * output reflect bitreverse result - * reciprocal bitreverse polynome - - These terms are explained at - http://www.sunshine2k.de/articles/coding/crc/understanding_crc.html - - The 32 bit DIGEST <polynome> command defines some global symbols. - ___CRC32___ is the address of the CRC64 checksum - ___CRC32_START___ is the address where CRC calculation starts - ___CRC32_END___ The CRC calculation ends before this address. - - The 64-bit DIGEST <polynome> command defines some global symbols. - ___CRC64___ is the address of the CRC64 checksum - ___CRC64_START___ is the address where CRC calculation starts - ___CRC64_END___ The CRC calculation ends before this address. - - All three symbols must refer to addresses in the selected section. - If they are defined at the end of the linking process, then - the CRC## will be calculated between - - ___CRC##_START___ .. ___CRC##_END___ -1 - - and the result will be inserted at ___CRC##___. - - ___CRC##___ must be outside the region where CRC is calculated - - The DIGEST TABLE command generates a table for CRC generation. - A table is not neccessary, but will speed up the calculation. - It defines the ___CRC##_TABLE___ symbol at the start of the table. - The user may choose to add this table to his code instead of using - the linker. - * The linker script syntax has two new commands for inserting text into output sections: ASCII (<size>) "string" @@ -110,16 +41,16 @@ Changes in 2.39: re-enabled via the --warn-rwx-segments option. New configure options can also control these new features: - + --enable-warn-execstack=no will disable the warnings about creating an executable stack. - + --enable-warn-execstack=yes will make --warn-execstack enabled by default. - + --enable-warn-rwx-segments=no will make --no-warn-rwx-segments enabled by default. - + --enable-default-execstack=no will stop the creation of an executable stack simply because an input file is missing a .note.GNU-stack section, even on architectures where this |