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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:29:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:29:49 +0000 |
commit | 1fd7da94235a7ee9cc21d25d39e6c03421ef5ab6 (patch) | |
tree | b4cc647f3e5833b224c5fd593023397a80cca78f /docs/framebuffer | |
parent | Initial commit. (diff) | |
download | initramfs-tools-1fd7da94235a7ee9cc21d25d39e6c03421ef5ab6.tar.xz initramfs-tools-1fd7da94235a7ee9cc21d25d39e6c03421ef5ab6.zip |
Adding upstream version 0.140.upstream/0.140upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/framebuffer')
-rw-r--r-- | docs/framebuffer | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/docs/framebuffer b/docs/framebuffer new file mode 100644 index 0000000..81ba77f --- /dev/null +++ b/docs/framebuffer @@ -0,0 +1,116 @@ +#!/bin/sh + +PREREQ="" +prereqs() +{ + echo "$PREREQ" +} +case $1 in +# get pre-requisites +prereqs) + prereqs + exit 0 + ;; +esac + + +# The options part of the kernel "video=" argument (i.e. everyting +# after "video=<fbdriver>:") has very inconsistent rules. +# +# Generally the following applies: +# 1) options are comma-separated +# 2) options can be in either of these three forms: +# <arg>=<value>, <arg>:<value>, <boolean-arg>. +# 3) the "mode" or "mode_option" option (name depends on the framebuffer driver) +# has the form <xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m] +# and may or may not start with "mode=" or "mode_option=" +# -> please adjust as necessary in the parse_video_opts() function +# +# When the options are used with modules, they need to be space-separated +# and the following conversions are needed: +# <arg>:<value> -> <arg>=<value> +# <boolean-arg> -> <boolean-arg>=1 +# <modevalue> -> mode=<modevalue> or mode_option=<modevalue> +parse_video_opts() +{ + local OPTS="$1" + local IFS="," + + # Must be a line like video=<fbdriver>:<opt1>,[opt2]... + if [ "${OPTS}" = "${OPTS%%:*}" ]; then + return + fi + OPTS="${OPTS#*:}" + for opt in ${OPTS}; do + # Already in the "<arg>=<value>" form + if [ "${opt}" != "${opt#*=}" ]; then + printf "%s" "$opt " + # In the "<arg>:<value>" form + elif [ "${opt}" != "${opt#*:}" ]; then + printf "%s" "${opt%:*}=${opt#*:} " + # Presumably a modevalue without the "mode=" prefix + elif [ "${opt}" != "${opt#[0-9]*x[0-9]}" ]; then + # Adjust: mode= option? + printf "%s" "mode=$opt " + # ... or mode_option= option? + # printf "%s" "mode_option=$opt " + # Presumably a boolean + else + printf "%s" "${opt}=1 " + fi + done +} + +FB="" +OPTS="" + +# shellcheck disable=SC2013 +for x in $(cat /proc/cmdline); do + case ${x} in + vga=*) + FB="vesafb"; + OPTS=""; + ;; + video=*) + FB=${x#*=} + FB="${FB%%:*}" + OPTS="$(parse_video_opts "${x}")" + esac +done + +# Module-specific workarounds +case ${FB} in +matroxfb) + # Map command line name to module name + FB=matroxfb_base + ;; +intelfb|i810fb|i915) + # Needs AGP driver loaded + modprobe intel-agp + ;; +uvesafb) + # v86d requires /dev/zero and dev/mem, but udev haven't been started yet + [ -e /dev/zero ] || mknod -m 0666 /dev/zero c 1 5 + [ -e /dev/mem ] || mknod -m 0640 /dev/mem c 1 1 + ;; +*) + ;; +esac + +if [ -n "${FB}" ]; then + unset MODPROBE_OPTIONS + modprobe -q fbcon + # shellcheck disable=SC2086 + modprobe -q ${FB} ${OPTS} +fi + +if [ -e /proc/fb ]; then + # shellcheck disable=SC2034 + while read -r fbno desc; do + if [ $((fbno < 32)) ]; then + mknod -m 0640 "/dev/fb${fbno}" c 29 "${fbno}" + fi + done < /proc/fb +else + mknod -m 0640 /dev/fb0 c 29 0 +fi |