Struct KdumpBuilder 

pub struct KdumpBuilder { /* private fields */ }

Build a synthetic kdump (makedumpfile) dump for testing.

Produces the disk_dump_header + kdump_sub_header + bitmaps + page descriptors + compressed page data layout used by makedumpfile and crash-utility.

File layout (block_size = 4096 by default):

• Block 0: disk_dump_header
• Block 1: kdump_sub_header (mostly zeros for test)
• Blocks 2..2+N: 1st bitmap (valid PFNs)
• Blocks 2+N..2+2N: 2nd bitmap (dumped PFNs)
• After bitmaps: page_desc[] array (24 bytes each, block-aligned)
• After descs: compressed page data

disk_dump_header (Block 0):

• 0x00: signature “KDUMP “ (8 bytes, 3 trailing spaces)
• 0x08: header_version = 6 (i32)
• 0x0C: utsname (390 bytes = 6 fields * 65, zeros)
• Aligned to 4 after utsname: block_size(i32) + sub_hdr_size(i32=1) + bitmap_blocks(u32) + max_mapnr(u32)

page_desc (24 bytes each):

• offset: i64 (file offset of compressed data)
• size: u32 (compressed size)
• flags: u32 (compression method)
• page_flags: u64 (kernel flags, 0 for test)

Implementations

impl KdumpBuilder

pub fn new() -> Self

Create a new builder with defaults: block_size=4096, compression=snappy (0x04).

pub fn block_size(self, bs: u32) -> Self

Set the block size (must be a power of 2, typically 4096).

pub fn compression(self, flags: u32) -> Self

Set the compression flags for page data.

• 0x00: uncompressed
• 0x01: zlib
• 0x04: snappy
• 0x20: zstd (stored as minimal zstd frame)

pub fn add_page(self, pfn: u64, data: &[u8]) -> Self

Add a physical page at the given PFN with data (must be exactly block_size bytes).

pub fn build(self) -> Vec<u8>

Build the complete kdump file as a byte vector.

Trait Implementations

impl Default for KdumpBuilder

fn default() -> Self

Returns the “default value” for a type.