Replace size reporting with sysfs helper; keep fdisk for partition tables

fdisk -l can’t be trusted inside Heads’ initrd: busybox limits it to
2 TiB and parsing its output is fragile.

Changes relative to origin/master:

  * add new function disk_info_sysfs() in initrd/etc/functions
    – walks /sys/block, skips partition entries, and computes a byte
      count (preferring blockdev --getsize64, otherwise size*512)
    – converts to decimal GB, switching to TB for ≥1000 GB
  * update show_system_info() (gui_functions & oem‑system‑info‑xx30) to call the
    helper and no longer invoke `fdisk -l` for size output
  * add TRACE_FUNC/DEBUG logging around the helper invocation

Tested in qemu/debian‑13/PureOS; only the size line differs, other behaviour
is identical to master.

Signed-off-by: Thierry Laurion <insurgo@riseup.net>

Author: tlaurion

initrd/bin/oem-system-info-xx30

@@ -59,5 +59,8 @@ fi
 ec_ver_line=""
 [ -n "$EC_VER" ] && ec_ver_line="\nEC_VER: ${EC_VER}"
 
+# gather disk info via helper (avoids busybox 2TB limit)
+disk_info="$(disk_info_sysfs)"
+
 whiptail_type $BG_COLOR_MAIN_MENU $FB_OPTIONS --title 'System Info' \
-	--msgbox "${BOARD_NAME}\nFW_VER: ${FW_VER}${ec_ver_line}\nKernel: ${kernel}\nCPU: ${cpustr}  RAM: ${memtotal} GB $battery_status\n$(fdisk -l | grep -e '/dev/sd.:' -e '/dev/nvme.*:' | sed 's/B,.*/B/')\n\n$(cat /tmp/devices_usb_pci)" 0 80
+	--msgbox "${BOARD_NAME}\nFW_VER: ${FW_VER}${ec_ver_line}\nKernel: ${kernel}\nCPU: ${cpustr}  RAM: ${memtotal} GB $battery_status\n${disk_info}\n\n$(cat /tmp/devices_usb_pci)" 0 80

initrd/etc/functions

@@ -822,6 +822,45 @@ device_has_partitions() {
 	return 0
 }
 
+# Build displayable disk information using sysfs (vs current busybox's 2tb limit per https://bugs.busybox.net/show_bug.cgi?id=16276)
+# Output format: "Disk /dev/<name>: <GB> GB" per line
+# The /sys/block/*/size entry is always counted in 512-byte sectors, so
+# calculate using bytes from blockdev when available or multiply by 512.
+disk_info_sysfs() {
+	TRACE_FUNC
+	local disk_info=""
+	for dev in /sys/block/sd* /sys/block/nvme* /sys/block/vd* /sys/block/hd*; do
+		if [ -e "$dev" ]; then
+			# ignore partition entries (they contain a 'partition' file)
+			if [ -e "$dev/partition" ]; then
+				continue
+			fi
+			local devname=$(basename "$dev")
+			local size_bytes=""
+			if command -v blockdev >/dev/null 2>&1; then
+				size_bytes=$(blockdev --getsize64 "/dev/${devname}" 2>/dev/null)
+			fi
+			if [ -z "$size_bytes" ] || ! [ "$size_bytes" -gt 0 ] 2>/dev/null; then
+				local size_sectors_512=$(cat "$dev/size" 2>/dev/null)
+				if [ -n "$size_sectors_512" ] && [ "$size_sectors_512" -gt 0 ] 2>/dev/null; then
+					size_bytes=$((size_sectors_512 * 512))
+				fi
+			fi
+			if [ -n "$size_bytes" ] && [ "$size_bytes" -gt 0 ] 2>/dev/null; then
+				local size_gb=$(((size_bytes + 500000000) / 1000000000))
+				# show TB when >= 1000 GB for better UX
+				if [ "$size_gb" -ge 1000 ]; then
+					local size_tb=$(((size_bytes + 500000000000) / 1000000000000))
+					printf -v disk_info "%sDisk /dev/%s: %s TB\n" "$disk_info" "$devname" "$size_tb"
+				else
+					printf -v disk_info "%sDisk /dev/%s: %s GB\n" "$disk_info" "$devname" "$size_gb"
+				fi
+			fi
+		fi
+	done
+	printf "%s" "$disk_info"
+}
+
 list_usb_storage() {
 	TRACE_FUNC
 	# List all USB storage devices, including partitions unless we received argument stating we want drives only
@@ -1259,24 +1298,29 @@ find_lvm_vg_name() {
 # GPT-partitioned disk.
 is_gpt_bios_grub() {
 	TRACE_FUNC
+	DEBUG "is_gpt_bios_grub: PART_DEV=$1"
 
 	local PART_DEV="$1" DEVICE NUMBER
 
 	# Figure out the partitioned device containing this device (if there is
 	# one) from /sys/class/block.
 	local DEVICE_MATCHES=("/sys/class/block/"*"/$(basename "$PART_DEV")")
+	DEBUG "is_gpt_bios_grub: DEVICE_MATCHES=${DEVICE_MATCHES[*]}"
 
 	DEVICE="$(echo "${DEVICE_MATCHES[0]}" | cut -d/ -f5)"
 	if [ "${#DEVICE_MATCHES[@]}" -ne 1 ] || [ "$DEVICE" = "*" ]; then
+		DEBUG "is_gpt_bios_grub: ambiguous DEVICE, returning false"
 		return 0
 	fi
 
 	# Extract the partition number
 	if ! [[ $(basename "$PART_DEV") =~ ([0-9]+)$ ]]; then
+		DEBUG "is_gpt_bios_grub: cannot parse partition number"
 		return 0 # Can't figure out the partition number
 	fi
 
 	NUMBER="${BASH_REMATCH[1]}"
+	DEBUG "is_gpt_bios_grub: DEVICE=$DEVICE NUMBER=$NUMBER"
 
 	# Now we know the device and partition number, get the type.  This is
 	# specific to GPT disks, MBR disks are shown differently by fdisk.

initrd/etc/gui_functions

@@ -182,6 +182,10 @@ show_system_info() {
 	[ -n "$EC_VER" ] && ec_ver_line="
 	EC_VER: ${EC_VER}"
 
+	local disk_info="$(disk_info_sysfs)"
+	TRACE_FUNC
+	DEBUG "show_system_info: disk_info=\n${disk_info}"
+
 	local msgbox="${BOARD_NAME}
 
 	FW_VER: ${FW_VER}${ec_ver_line}
@@ -191,7 +195,7 @@ show_system_info() {
 	Microcode: $(cat /proc/cpuinfo | grep microcode | uniq | cut -d':' -f2 | tr -d ' ')
 	RAM: ${memtotal} GB
 	$battery_status
-	$(fdisk -l 2>/dev/null | grep -e '/dev/sd.:' -e '/dev/nvme.*:' | sed 's/B,.*/B/')
+	${disk_info}
 	"
 
 	local msgbox_rm_tabs=$(echo "$msgbox" | tr -d "\t")