liminix/modules/outputs/tftpboot.nix
Raito Bezarius 5b5b527f92 tftp: introduce the FIT enclosing boot.scr
This simplify TFTP.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>
2024-08-26 17:59:24 +02:00

199 lines
7 KiB
Nix

{
config
, pkgs
, lib
, ...
}:
let
inherit (lib) mkOption types concatStringsSep;
cfg = config.boot.tftp;
hw = config.hardware;
arch = pkgs.stdenv.hostPlatform.linuxArch;
in {
imports = [ ../ramdisk.nix ];
options.boot.tftp = {
freeSpaceBytes = mkOption {
type = types.int;
default = 0;
};
kernelFormat = mkOption {
type = types.enum [ "zimage" "uimage" ];
default = "uimage";
};
compressRoot = mkOption {
type = types.bool;
default = false;
};
appendDTB = mkOption {
type = types.bool;
default = false;
};
};
options.system.outputs = {
tftpboot = mkOption {
type = types.package;
description = ''
tftpboot
********
This output is intended for developing on a new device.
It assumes you have a serial connection and a
network connection to the device and that your
build machine is running a TFTP server.
The output is a directory containing kernel and
root filesystem image, and a script :file:`boot.scr` of U-Boot
commands that will load the images into memory and
run them directly,
instead of first writing them to flash. This saves
time and erase cycles.
It uses the Linux `phram <https://github.com/torvalds/linux/blob/master/drivers/mtd/devices/phram.c>`_ driver to emulate a flash device using a segment of physical RAM.
'';
};
tftpboot-fit = mkOption {
type = types.package;
description = ''
tftpboot-fit
************
This output is a variant that encloses the `boot.scr` in a FIT
if that's simpler to transfer for you.
'';
};
};
config = {
boot.ramdisk.enable = true;
system.outputs = rec {
tftpboot-fit =
let
tftpboot-fit = pkgs.writeText "tftpboot.its" ''
/dts-v1/;
/ {
description = "Liminix TFTP bootscript";
#address-cells = <1>;
images {
bootscript {
description = "Bootscript";
data = /incbin/("${tftpboot}/boot.scr");
type = "script";
compression = "none";
};
};
};
'';
in
pkgs.runCommand "tftpboot-fit" { nativeBuildInputs = with pkgs.pkgsBuildBuild; [ ubootTools ]; } ''
mkdir -p $out/
cp -rf ${tftpboot}/* $out/
mkimage -f ${tftpboot-fit} $out/script.ub
'';
tftpboot =
let
inherit (pkgs.lib.trivial) toHexString;
o = config.system.outputs;
image = let choices = {
uimage = o.uimage;
zimage = o.zimage;
}; in choices.${cfg.kernelFormat};
bootCommand = let choices = {
uimage = "bootm";
zimage = "bootz";
}; in choices.${cfg.kernelFormat};
cmdline = concatStringsSep " " config.boot.commandLine;
objcopy = "${pkgs.stdenv.cc.bintools.targetPrefix}objcopy";
stripAndZip = ''
${objcopy} -O binary -R .reginfo -R .notes -R .note -R .comment -R .mdebug -R .note.gnu.build-id -S vmlinux.elf vmlinux.bin
rm -f vmlinux.bin.lzma ; lzma -k -z vmlinux.bin
'';
in
pkgs.runCommand "tftpboot" { nativeBuildInputs = with pkgs.pkgsBuildBuild; [ lzma dtc pkgs.stdenv.cc ubootTools ]; } ''
mkdir $out
cd $out
binsize() { local s=$(stat -L -c %s $1); echo $(($s + 0x1000 &(~0xfff))); }
binsize64k() { local s=$(stat -L -c %s $1); echo $(($s + 0x10000 &(~0xffff))); }
hex() { printf "0x%x" $1; }
rootfsStart=${toString cfg.loadAddress}
rootfsSize=$(binsize64k ${o.rootfs} )
rootfsSize=$(($rootfsSize + ${toString cfg.freeSpaceBytes} ))
ln -s ${o.manifest} manifest
ln -s ${o.kernel} vmlinux # handy for gdb
# if we are transferring kernel and dtb separately, the
# dtb has to precede the kernel in ram, because zimage
# decompression code will assume that any memory after the
# end of the kernel is free
dtbStart=$(($rootfsStart + $rootfsSize))
${if cfg.compressRoot
then ''
lzma -z9cv ${o.rootfs} > rootfs.lz
rootfsLzStart=$dtbStart
rootfsLzSize=$(binsize rootfs.lz)
dtbStart=$(($dtbStart + $rootfsLzSize))
''
else ''
ln -s ${o.rootfs} rootfs
''
}
cat ${o.dtb} > dtb
address_cells=$(fdtget dtb / '#address-cells')
size_cells=$(fdtget dtb / '#size-cells')
if [ $address_cells -gt 1 ]; then ac_prefix=0; fi
if [ $size_cells -gt 1 ]; then sz_prefix=0; fi
fdtput -p dtb /reserved-memory '#address-cells' $address_cells
fdtput -p dtb /reserved-memory '#size-cells' $size_cells
fdtput -p dtb /reserved-memory ranges
node=$(printf "phram-rootfs@%x" $rootfsStart)
fdtput -p -t s dtb /reserved-memory/$node compatible phram
fdtput -p -t lx dtb /reserved-memory/$node reg $ac_prefix $(hex $rootfsStart) $sz_prefix $(hex $rootfsSize)
cmd="liminix ${cmdline} mtdparts=phram0:''${rootfsSize}(rootfs) phram.phram=phram0,''${rootfsStart},''${rootfsSize},${toString config.hardware.flash.eraseBlockSize} root=/dev/mtdblock0";
fdtput -t s dtb /chosen ${config.boot.commandLineDtbNode} "$cmd"
dtbSize=$(binsize ./dtb )
${if cfg.appendDTB then ''
imageStart=$dtbStart
# re-package image with updated dtb
cat ${o.kernel} > vmlinux.elf
${objcopy} --update-section .appended_dtb=dtb vmlinux.elf
${stripAndZip}
mkimage -A ${arch} -O linux -T kernel -C lzma -a $(hex ${toString hw.loadAddress}) -e $(hex ${toString hw.entryPoint}) -n '${lib.toUpper arch} Liminix Linux tftpboot' -d vmlinux.bin.lzma image
# dtc -I dtb -O dts -o /dev/stdout dtb | grep -A10 chosen ; exit 1
tftpcmd="tftpboot $(hex $imageStart) result/image "
bootcmd="bootm $(hex $imageStart)"
'' else ''
imageStart=$(($dtbStart + $dtbSize))
tftpcmd="tftpboot $(hex $imageStart) result/image; tftpboot $(hex $dtbStart) result/dtb "
ln -s ${image} image
bootcmd="${bootCommand} $(hex $imageStart) - $(hex $dtbStart)"
''}
cat > boot.scr << EOF
setenv serverip ${cfg.serverip}
setenv ipaddr ${cfg.ipaddr}
${
if cfg.compressRoot
then "tftpboot $(hex $rootfsLzStart) result/rootfs.lz"
else "tftpboot $(hex $rootfsStart) result/rootfs"
}; $tftpcmd
${if cfg.compressRoot
then "lzmadec $(hex $rootfsLzStart) $(hex $rootfsStart); "
else ""
} $bootcmd
EOF
'';
};
};
}