segment.h File Reference

Executable image segments. More...

#include <stdint.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
int	prep_segment (void *segment, size_t filesz, size_t memsz)
	Prepare segment for loading. More...

Detailed Description

Executable image segments.

Definition in file segment.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

prep_segment()

int prep_segment	(	void *	segment,
		size_t	filesz,
		size_t	memsz
	)

Prepare segment for loading.

Parameters

segment	Segment start
filesz	Size of the "allocated bytes" portion of the segment
memsz	Size of the segment

Return values

rc	Return status code

Definition at line 61 of file segment.c.

                                                                {
        struct memmap_region region;
        physaddr_t start = virt_to_phys ( segment );
        physaddr_t mid = ( start + filesz );
        physaddr_t end = ( start + memsz );
        physaddr_t max;

        DBGC ( segment, "SEGMENT [%#08lx,%#08lx,%#08lx)\n", start, mid, end );

        /* Check for malformed lengths */
        if ( filesz > memsz ) {
                DBGC ( segment, "SEGMENT [%#08lx,%#08lx,%#08lx) is "
                       "malformed\n", start, mid, end );
                return -EINVAL;
        }

        /* Zero-length segments do not need a memory region */
        if ( memsz == 0 )
                return 0;
        max = ( end - 1 );

        /* Check for address space overflow */
        if ( max < start ) {
                DBGC ( segment, "SEGMENT [%#08lx,%#08lx,%#08lx) wraps "
                       "around\n", start, mid, end );
                return -EINVAL;
        }

        /* Describe region containing this segment */
        memmap_describe ( start, 1, &region );
        DBGC_MEMMAP ( segment, &region );

        /* Fail unless region is usable and sufficiently large */
        if ( ( ! memmap_is_usable ( &region ) ) || ( region.max < max ) ) {
                DBGC ( segment, "SEGMENT [%#08lx,%#08lx,%#08lx) does not fit "
                       "into available memory\n", start, mid, end );
                return -ERANGE_SEGMENT;
        }

        /* Found valid region: zero bss and return */
        memset ( ( segment + filesz ), 0, ( memsz - filesz ) );
        return 0;
}

References DBGC, DBGC_MEMMAP, EINVAL, end, ERANGE_SEGMENT, max, memmap_region::max, memmap_describe(), memmap_is_usable(), memset(), memsz, mid, segment, and start.

Referenced by bzimage_exec(), com32_load_image(), com32_prepare_bounce_buffer(), comboot_prepare_segment(), elf_load_segment(), lkrn_exec(), multiboot_add_modules(), multiboot_load_raw(), nbi_prepare_segment(), and pxe_exec().