1 files changed, 58 insertions, 0 deletions
diff --git a/elf/header.lua b/elf/header.lua
new file mode 100644
index 0000000..2a9ec68
--- /dev/null
+++ b/elf/header.lua
@@ -0,0 +1,58 @@
+local fmt = require("elf.fmt")
+
+local M = {}
+
+---@alias Magic [integer, integer, integer, integer]
+
+---@class Header
+---@field magic Magic
+---@field class Class
+---@field data Endian
+---@field ident_version integer
+---@field osabi Osabi
+---@field abiversion integer
+---@field type Type
+---@field machine Machine
+---@field version integer
+---@field entry integer
+---@field phoff integer
+---@field shoff integer
+---@field flags integer
+---@field ehsize integer
+---@field phentsize? integer
+---@field phnum? integer
+---@field shentsize integer
+---@field shnum integer
+---@field shstrndx integer
+
+---@param hdr Header
+---@return string
+---@nodiscard
+function M.pack(hdr)
+    return string.pack("BBBBBBBBBxxxxxxx" ..
+        fmt.endian(hdr.data) ..
+        "I2I2I4" ..
+        string.rep(fmt.word(hdr.class), 3) ..
+        "I4I2I2I2I2I2I2",
+        hdr.magic[1], hdr.magic[2], hdr.magic[3], hdr.magic[4],
+        hdr.class,
+        hdr.data,
+        hdr.ident_version,
+        hdr.osabi,
+        hdr.abiversion,
+        hdr.type,
+        hdr.machine,
+        hdr.version,
+        hdr.entry,
+        hdr.phoff,
+        hdr.shoff,
+        hdr.flags,
+        hdr.ehsize,
+        hdr.phentsize,
+        hdr.phnum,
+        hdr.shentsize,
+        hdr.shnum,
+        hdr.shstrndx)
+end
+
+return M