libre: uboot4extlinux-sunxi: lower maintenance costs

- We can now do cross builds of u-boot:
  - We can now more easily work on the package as we don't need
    an ARM computer for that anymore.
  - It also enable people already using Parabola on x86 to more
    easily install, test, or repair u-boot for an ARM computer
    as users can simply install it on microSD cards without
    needing to use ARM chroots.
- There is now an install script to install u-boot:
  - It makes things easier for users as it is more similar to
    grub-install than dd commands.
  - It also does many checks at the same time to avoid data loss.
- The commands to split packages are now shared between all
  package_ functions. This lower maintenance.
- How to add a new board has been made more clear.

Comparison with other distributions (for consistency):
- u-boot doesn't have anything to handle the installation and
  update of u-boot binaries if UEFI is not used.
- Debian has an u-boot-install-sunxi script which handles way more
  cases than what I wrote (it even handles GPT and so on and even
  has a manual), but there seems to be no tools to update u-boot.
- Openembedded doesn't seem to have anything special in
  the u-boot recipe in openembedded-core

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

1 files changed, 141 insertions, 0 deletions

diff --git a/libre/uboot4extlinux-sunxi/generate-uboot4extlinux-sunxi-install-text.sh b/libre/uboot4extlinux-sunxi/generate-uboot4extlinux-sunxi-install-text.sh
new file mode 100644
index 000000000..e8c9c29a9
--- /dev/null
+++ b/libre/uboot4extlinux-sunxi/generate-uboot4extlinux-sunxi-install-text.sh
@@ -0,0 +1,141 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2020 Denis 'GNUtoo' Carikli
+
+line_length=81
+
+printchar()
+{
+    char="$1"
+    nr_chars="$2"
+
+    if [ -z "${nr_chars}" ] ; then
+        echo -n "${char}"
+    else
+        i=0
+        while [ $i -lt ${nr_chars} ] ; do
+            echo -n "${char}"
+            i=$(expr $i + 1)
+        done
+    fi
+}
+
+print_separation_line()
+{
+    echo -n "+"
+    printchar "-" $(expr ${line_length} - 2)
+    echo  "+"
+}
+
+strlen()
+{
+    echo $(expr $(echo "$1" | wc -c) - 1)
+}
+
+print_header()
+{
+    pkgname="$1"
+
+    # ${line_length}
+    # - '| '
+    # - ${pkgname}
+    # - ' '
+    # - 'installation instructions:'
+    # - ' |'
+    extra_spaces=$(expr ${line_length} - 2 - $(strlen "${pkgname}") - 1)
+    extra_spaces=$(expr ${extra_spaces} - \
+                $(strlen "installation instructions:") - 2)
+
+    print_separation_line
+    echo -n "| "
+    echo -n "${pkgname} installation instructions:"
+    printchar " " "${extra_spaces}"
+    echo " |"
+    print_separation_line
+}
+
+print_line()
+{
+    line="$1"
+
+    # ${line_length} - '| ' - ${line} -  ' |'
+    extra_spaces=$(expr ${line_length} - 2 - $(strlen "${line}") - 2)
+    echo -n '| '
+    echo -n "${line}"
+    printchar " " "${extra_spaces}"
+    echo ' |'
+}
+
+print_text()
+{
+    for line in "$@" ; do
+        print_line "${line}"
+    done
+}
+
+print_introduction()
+{
+    print_text \
+        "To boot with u-boot you will need to do two things:" \
+        "- First you will need to install u-boot to the storage device (like" \
+        "  a microSD) you will be booting from. You can consult the Parabola" \
+        "  installation instructions to know which storage devices are" \
+        "  supported." \
+        "- Then you will need to read and potentially modify the" \
+        "  /boot/extlinux/extlinux.conf configuration file to tell u-boot" \
+        "  from which kernel to boot, and various other settings related to" \
+        "  booting (like LVM or disk encryption settings)."
+}
+
+print_uboot_install_instructions()
+{
+    pkgname="$1"
+    install_script="$2"
+
+    print_text \
+           "To install or upgrade u-boot you can use similar commands:" \
+           "    cd $(dirname ${script})" \
+           "    sudo ./$(basename ${script}) <path/to/block-device>"
+
+    print_line ""
+
+    print_text \
+       "For instance if the microSD you (will) boot from is available at" \
+       "/dev/mmcblk0 you can use the following commands:" \
+           "    cd $(dirname ${script})" \
+           "    sudo ./$(basename ${script}) /dev/mmcblk0"
+
+    print_line ""
+
+    print_text \
+       "Instead if the microSD is available at /dev/sdb you can use the" \
+       "following commands:" \
+           "    cd $(dirname ${script})" \
+           "    sudo ./$(basename ${script}) /dev/sdb"
+}
+
+print_extlinux_config_remainder()
+{
+    pkgbase="$1"
+
+    print_text \
+       "When this is done you'll need to create and/or modify the" \
+       "/boot/extlinux/extlinux.conf configuration file."
+    print_line ""
+
+    print_text \
+        "There is an example file for that at" \
+        "/usr/lib/u-boot/${pkgbase}/extlinux.conf"
+}
+
+pkgname="$1"
+pkgbase="$2"
+script="$3"
+
+print_header "${pkgname}"
+print_introduction
+print_line " "
+print_uboot_install_instructions "${pkgname}" "${script}"
+print_line " "
+print_extlinux_config_remainder "${pkgbase}"
+print_separation_line