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ipxe/src/arch/i386/core/etherboot.prefix.lds

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OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
OUTPUT_ARCH(i386)
ENTRY(_prefix_start)
SECTIONS {
/* Prefix */
.prefix : {
_verbatim_start = . ;
_prefix_start = . ;
*(.prefix)
. = ALIGN(16);
_prefix_end = . ;
} = 0x9090
_prefix_size = _prefix_end - _prefix_start;
.text.nocompress : {
*(.prefix.udata)
} = 0x9090
decompress_to = . ;
.prefix.zdata : {
_compressed = . ;
*(.prefix.zdata)
_compressed_end = . ;
}
_compressed_size = _compressed_end - _compressed;
. = ALIGN(16);
_verbatim_end = . ;
/* Size of the core of etherboot in memory */
_base_size = _end - _text;
/* _prefix_size is the length of the non-core etherboot prefix */
_prefix_size = _prefix_end - _prefix_start;
/* _verbatim_size is the actual amount that has to be copied to base memory */
_verbatim_size = _verbatim_end - _verbatim_start;
/* _image_size is the amount of base memory needed to run */
_image_size = _base_size + _prefix_size;
/* Standard sizes rounded up to paragraphs */
_prefix_size_pgh = (_prefix_size + 15) / 16;
_verbatim_size_pgh = (_verbatim_size + 15) / 16;
_image_size_pgh = (_image_size + 15) / 16 ;
/* Standard sizes in sectors */
_prefix_size_sct = (_prefix_size + 511) / 512;
_verbatim_size_sct = (_verbatim_size + 511) / 512;
_image_size_sct = (_image_size + 511) / 512;
/* Symbol offsets and sizes for the exe prefix */
_exe_hdr_size = 32;
_exe_size = _verbatim_size; /* Should this be - 32 to exclude the header? */
_exe_size_tail = (_exe_size) % 512;
_exe_size_pages = ((_exe_size) + 511) / 512;
_exe_bss_size = ((_image_size - _verbatim_size) + 15) / 16;
_exe_ss_offset = (_stack_offset + _prefix_size - _exe_hdr_size + 15) / 16 ;
/* This is where we copy the compressed image before decompression.
* Prepare to decompress in place. The end mark is about 8.25 bytes long,
* and the worst case symbol is about 16.5 bytes long. Therefore
* We need to reserve at least 25 bytes of slack here.
* Currently I reserve 2048 bytes of just slack to be safe :)
* 2048 bytes easily falls within the BSS (the defualt stack is 4096 bytes)
* so we really are decompressing in place.
*
* Hmm. I missed a trick. In the very worst case (no compression)
* the encoded data is 9/8 the size as it started out so to be completely
* safe I need to be 1/8 of the uncompressed code size past the end.
* This will still fit compfortably into our bss in any conceivable scenario.
*/
_compressed_copy = _edata + _prefix_size - _compressed_size +
/* The amount to overflow _edata */
MAX( ((_edata - _text + 7) / 8) , 2016 ) + 32;
_assert = ASSERT( ( _compressed_copy - _prefix_size ) < _ebss , "Cannot decompress in place" ) ;
decompress = DEFINED(decompress) ? decompress : 0;
/DISCARD/ : {
*(.comment)
*(.note)
}
/* Symbols used by the prefixes whose addresses are inconvinient
* to compute, at runtime in the code.
*/
image_basemem_size = DEFINED(image_basemem_size)? image_basemem_size : 65536;
image_basemem = DEFINED(image_basemem)? image_basemem : 65536;
_prefix_real_to_prot = _real_to_prot + _prefix_size ;
_prefix_prot_to_real = _prot_to_real + _prefix_size ;
_prefix_image_basemem_size = image_basemem_size + _prefix_size ;
_prefix_image_basemem = image_basemem + _prefix_size ;
_prefix_rm_in_call = _rm_in_call + _prefix_size ;
_prefix_in_call = _in_call + _prefix_size ;
_prefix_rom = rom + _prefix_size ;
_prefix_rm_etherboot_location = rm_etherboot_location + _prefix_size ;
_prefix_stack_end = _stack_end + _prefix_size ;
}