local version=cpio.new_version 'version'
package.cpath=package.cpath..';files/lib/?.so'
elf = require 'elfutil'
ffi = require 'ffi'
ffi.cdef 'int access(const char *path, int mode);'

local output=io.popen('lzma -3 >'..cpio.cwd..'/minboot.lzma', 'w')
cpio.set_output(output)

local verfile=assert(io.open('.version', 'w'))
verfile:write(version..' - '..cpio.time_now('%F')..'\n')
verfile:close()

local stored = {}
local function file(names, source, mode)
   assert(not stored[source], 'Duplicated store of: '..source)
   stored[source] = source ~= '/dev/null'
   cpio.emit_file(names, source, mode, 0, 0)
end

pprint = require 'pprint'

local needed = {}
local satisfied = {}
local function exec(names, source)
   file(names, source, '0755')
   local results = elf.scan_elf(source)
   if results then
      local soname = results.soname
      if soname then
	 satisfied[soname] = true
	 needed[soname] = nil
      end
      for _, need in ipairs(results.needed) do
	 if not satisfied[need] then needed[need] = true end
      end
   end
end
local function slink(sources, target)
   cpio.emit_symlink(sources, target, '0777', 0, 0)
end

local function dir(path, mode) cpio.emit_directory(path, mode, 0, 0) end
local function nod(dev, mode, isblock, major, minor)
   cpio.emit_node('/dev/'..dev, mode, 0, 0, isblock, major, minor)
end

local pipe

file('.version', '.version', '0644')
file('.mkcpio', cpio.script, '0644')

local function dirs(path, mode)
   local subpath = ''
   for part in path:gmatch '([^/]+)/?' do
      subpath = subpath..part
      dir(subpath, mode)
      subpath = subpath..'/'
   end
end

for _,v in ipairs { 'bin', 'dev', 'dltool', 'etc/rc.d', 'etc/ssh',
		    'lib/firmware/radeon', 'lib/udev/rules.d',
		    'mnt', 'proc', 'sys', 'tmp',
		    'share/tabset', 'share/udhcpc', 'var/log',
		    'var/empty', 'var/run', 'dev/pts', 'run',
		    'share/lua/5.1', 'lib64/lua/5.1',
		    'root/stdirfs/files/bin'
}
do
   dirs(v, '0755')
end
slink('lib/lua', '/lib64/lua')
file('root/.screenrc', 'files/root/screenrc', '0644')
slink('.screenrc', '/root/.screenrc')
dir('root/.ssh', '0700')
file('root/.ssh/authorized_keys', 'files/root/ssh/authorized_keys', '0600')
exec('root/dolilo', 'files/root/dolilo')

slink('sbin', 'bin')
slink('libexec', 'bin')
slink('usr', '/')
slink('local', '/')
slink('lib/terminfo', '/root/.terminfo')

-- Configurations
for _,v in ipairs { 'HOSTNAME', 'fstab', 'group', 'hosts', 'inittab',
		    'networks', 'nsswitch.conf', 'passwd', 'services',
		    'syslog.conf', 'syslog.conf.remote', 'termcap', 'profile' }
do
   file('etc/'..v, 'files/etc/'..v, '0644')
end
for _,v in ipairs { 'ssh/ssh_known_hosts', 'ssh/ssh_config', 'ssh/sshd_config',
		    'ssh/host_key', 'ssh/host_key.pub' }
do
   file('etc/'..v, 'files/etc/'..v, '0600')
end

-- Scripts
exec('/etc/rc.d/rc.S', 'files/etc/rc.d/rc.S')

file('etc/ssh/moduli', '/etc/ssh/moduli', '0644')
file('etc/shadow', 'files/etc/shadow', '0640')
exec('share/udhcpc/default.script', 'files/share/udhcpc/default.script')

-- Lua support
for _,v in ipairs{'ffi+.lua', 'pprint.lua', 'zstd.lua'} do
   file('share/lua/5.1/'..v, '/usr/local/share/lua/5.1/'..v, '0644')
end
for _,v in ipairs{ 'freezer.so', 'twinmap.so', 'struct.so', 'taskman.so',
		   'strbuff.so' } do
   file('lib64/lua/5.1/'..v, '/usr/local/lib64/lua/5.1/'..v, '0755')
end
slink('lib64/lua/5.1/lua-freezer.so.0.0', 'freezer.so')
slink('lib64/lua/5.1/lua-twinmap.so.0.0', 'twinmap.so')
slink('lib64/lua/5.1/lua-strbuff.so.0.0', 'strbuff.so')

-- Firmware
for _,v in ipairs { 'RS780_me.bin', 'RS780_pfp.bin', 'R600_rlc.bin' } do
   file('/lib/firmware/radeon'..v, 'files/firmware/'..v, '0644')
end

-- Empty files
for _,v in ipairs { 'var/log/wtmp', 'var/log/lastlog', 'var/run/utmp',
		    'etc/issue', 'etc/mtab' }
do file(v, '/dev/null', '0644') end

-- Devices
for _,v in ipairs {
   {'mem', 1, 1}, {'kmem', 1, 2}, {'null', 1, 3} , {'port', 1, 4},
   {'zero', 1, 5}, {'full', 1, 7}, {'random', 1, 8}, {'urandom', 1, 9},
   {'tty', 5, 0}, {'console', 5, 1}, {'vcs', 7, 0}, {'mouse', 13, 32},
   {'psaux', 10, 1}}
do
   nod(v[1], '0644', false, v[2], v[3])
end

for n=0,7 do
   nod('tty'..n, '0644', false, 4, n)
   nod('ttyp'..n, '0644', false, 3, n)
   nod('ptyp'..n, '0644', false, 2, n)
end

for n=0,3 do
   nod('rd'..n, '0640', true, 1, n)
   nod('loop'..n, '0644', true, 7, n)
   nod('cua'..n, '0640', false, 5, 64+n)
   nod('ttyS'..n, '0640', false, 4, 64+n)
   nod('par'..n, '0640', false, 99, n)
end

-- DL Tool
do
   for _,f in ipairs { 'completions', 'dlspec', 'dltool.lua' } do
      file('dltool/'..f, 'files/dltool/'..f, '0644')
   end
   exec('dltool/dltool', 'files/dltool/dltool')
   exec('lib64/lua/5.1/elfutil.so', 'files/lib/elfutil.so')
   slink('root/dlspec', '/dltool/dlspec')
   slink('bin/dltool', '/dltool/dltool')
end

-- udev DM rules
for _, rule in ipairs { '10-dm.rules', '11-dm-lvm.rules', '13-dm-disk.rules',
			'69-dm-lvm-metad.rules',
			'60-block.rules', '95-dm-notify.rules' }
do
   file('lib/udev/rules.d/'..rule, '/lib/udev/rules.d/'..rule, '0644')
end


-- Terminfo support
do
   local terminfos={ 's/screen', 'v/vanilla', 'l/linux*',
                       'x/xterm*', 'r/rxvt*', 'v/vt10*' }
   local dst='root/.terminfo'
   local src = '/usr/share/terminfo'
   local dirs_made= {}
   dir(dst, '0755')
   for _,t in ipairs (terminfos)
   do
      local d,f=t:match '^(.*)/(.*)$'
      if not dirs_made[d] then
         dir(dst..'/'..d, '0755')
         dirs_made[d] = true
      end
      pipe = io.popen('cd '..src..' 1>/dev/null; find '..d..' -name '..f)
      for line in pipe:lines() do
         file(dst..'/'..line, src..'/'..line, '0644')
      end
      pipe:close()
   end
end
slink('.terminfo', '/root/.terminfo')

-- Custom utilities
pipe = io.popen 'cd files 1>/dev/null;find bin -mindepth 1'
for util in pipe:lines() do
   exec(util, 'files/'..util) end
pipe:close()
slink('init', '/bin/busybox')

-- Rebuilds for thinned dependencies
exec('lib64/libpcap.so.1', 'files/lib/libpcap.so.1.10.1')
exec('lib64/libprocps.so.8', 'files/lib/libprocps.so.8.0.3')
exec('lib64/libtirpc.so.3', 'files/lib/libtirpc.so.3.0.0')

-- NSS support isn't a load time dependency.
for _, nsstype in ipairs { 'compat', 'db', 'dns', 'files', 'hesiod', 'nis' } do
   local name='lib64/libnss_'..nsstype..'.so.2'; exec(name, '/'..name)
end

-- Busykbox symlinks
pipe = io.popen 'files/bin/busybox --list | grep -v reboot'
for link in pipe:lines() do
   slink('bin/'..link, 'busybox')
end
pipe:close()

-- stdirfs
file('root/stdirfs/version', 'files/root/stdirfs/version', '0644')
file('root/stdirfs/mkcpio.irfs', 'files/root/stdirfs/mkcpio.irfs', '0644')
file('root/stdirfs/files/init', 'files/root/stdirfs/files/init', '0644')
exec('root/stdirfs/files/bin/busybox', 'files/root/stdirfs/files/bin/busybox')

-- Utilities from system
for _,bins in ipairs {
   { '/sbin/', { 'badblocks', 'blkid', 'cryptsetup', 'debugfs', 'dumpe2fs',
		 'e2fsck', 'e2image', 'fsck', 'lilo', 'logsave', 'lvm',
		 'mklost+found', 'nameif', 'resize2fs', 'tune2fs', 'dmsetup',
		 'udevd', 'udevadm' }},
   { '/bin/', { 'cpio', 'dialog', 'mg', 'setterm' }},
   { '/usr/bin/', { 'ls', 'mksquashfs', 'ps', 'uuidgen', 'tcpdump', 'rsync',
		    'unsquashfs', 'xxhsum', 'zstd', 'zstdgrep', 'zstdless' }},
   { '/usr/sbin/', { 'ethtool', 'gpm', 'hdparm', 'smartctl', 'dmidecode' }},
   { '/usr/local/bin/', { 'lua', 'rlwrap' }},
   { '/usr/local/sbin/', { 'wipe', 'mkcpio' }},
   { '/usr/libexec/', { 'sftp-server' }}}
do for _,v in ipairs(bins[2]) do exec('bin/'..v, bins[1]..v) end end
exec({'bin/fsck.ext2', 'bin/fsck.ext3', 'bin/fsck.ext4', 'bin/fsck.ext4dev'},
   '/sbin/fsck.ext2')
exec({'bin/lzma', 'bin/xz', 'bin/lzcat', 'bin/xzcat', 'bin/unlzma',
      'bin/unxz' }, '/usr/bin/lzma')
exec({'bin/mke2fs', 'bin/mkfs.ext2', 'bin/mkfs.ext3', '/bin/mkfs.ext4',
      '/bin/mkfs.ext4dev' }, '/sbin/mke2fs')
slink('bin/e2label', 'tune2fs')
slink('bin/zstdcat', 'zstd')
slink('bin/zstdmt', 'zstd')
slink('bin/unzstd', 'zstd')
slink('bin/xxh32sum', 'xxhsum')
slink('bin/xxh64sum', 'xxhsum')
slink('bin/xxh128sum', 'xxhsum')

   
-- Generate LVM symlinks from usage message
pipe=io.popen 'lvm 2>&1'
repeat
   local line = pipe:read '*l'
until line:match '^[%s]+$'
local skip_lvm = { help=true }
while true do
   local line = pipe:read '*l'
   if not line then break end
   local cmd = line:match '^[%s]*([%S]+)'
   if not skip_lvm[cmd] then
      slink('bin/'..cmd, '/bin/lvm')
   end
end
pipe:close()

-- Copy in needed libraries
while next(needed) do
   local tbl = {}
   for missing in pairs(needed) do tbl[#tbl+1] = missing end
   for _, missing in ipairs(tbl) do
      if ffi.C.access('/lib64/'..missing, 1) == 0 then
	 exec('lib64/'..missing, '/lib64/'..missing)
      elseif ffi.C.access('/usr/lib64/'..missing, 1) == 0 then
	 exec('lib64/'..missing, '/usr/lib64/'..missing)
      elseif ffi.C.access('/usr/local/lib64/'..missing, 1) == 0 then
	 exec('lib64/'..missing, '/usr/local/lib64/'..missing)
      end
   end
end

cpio.emit_trailer()
cpio.set_output()
output:close()
os.remove '.version'