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+# Translations
+
+## Workflow
+
+- Build firmware using build.sh. That creates necessary files in the `lang` dir.
+- add messages that are new: investigate not-tran.txt, copy selected strings into `lang_add.txt` and run lang-add.sh
+- export PO files for translation: `lang-export.sh`
+- when translators finish their work use `lang-import.sh`
+
+## Files
+
+### `lang_en.txt`
+```
+#MSG_CRASH_DET_ONLY_IN_NORMAL c=20 r=4
+"Crash detection can\x0abe turned on only in\x0aNormal mode"
+```
+
+### `lang_en_*.txt`
+```
+#MSG_CRASH_DET_ONLY_IN_NORMAL c=20 r=4
+"Crash detection can\x0abe turned on only in\x0aNormal mode"
+"Crash detekce muze\x0abyt zapnuta pouze v\x0aNormal modu"
+```
+1. a comment - usually a MSG define with number of characters (c) and rows (r)
+2. English text
+3. translated text
+
+### `not_tran.txt`
+A simple list of strings that are not translated yet.
+
+### `not_used.txt`
+A list os strings not currently used in the firmware. May be removed from `lang_en_*.txt` files by hand.
+
+## Scripts
+
+### `config.sh`
+- Checks setup and sets auxiliary env vars used in many other scripts. 
+- Looks for env var `ARDUINO`. If not found/empty, a default `C:/arduino-1.8.5` is used.
+- Sets env var `CONFIG_OK=1` when all good, otherwise sets `CONFIG_OK=0`
+
+### `fw-build.sh`
+Joins firmware HEX and language binaries into one file.
+
+### `fw-clean.sh`
+
+### `lang-add.sh`
+Adds new messages into the dictionary regardless of whether there have been any older versions.
+
+### `lang-build.sh`
+Generates lang_xx.bin (language binary files) for the whole firmware build.
+
+Arguments:
+- `$1` : language code (`en`, `cz`, `de`, `es`, `fr`, `it`, `pl`) or `all`
+- empty/no arguments defaults to `all`
+
+Input: `lang_en.txt` or `lang_en_xx.txt`
+
+Output: `lang_xx.bin`
+
+Temporary files: `lang_xx.tmp` and `lang_xx.dat`
+
+Description of the process:
+The script first runs `lang-check.py $1` and removes empty lines and comments (and non-translated texts) into `lang_$1.tmp`.
+The tmp file now contains all translated texts (some of them empty, i.e. "").
+The tmp file is then transformed into `lang_$1.dat`, which is a simple dump of all texts together, each terminated with a `\x00`.
+Format of the `bin` file:
+- 00-01: `A5 5A`
+- 02-03: `B4 4B`
+- 04-05: 2B size
+- 06-07: 2B number of strings
+- 08-09: 2B checksum
+- 0A-0B: 2B lang code hex data: basically `en` converted into `ne`, i.e. characters swapped. Only `cz` is changed into `sc` (old `cs` ISO code).
+- 0C-0D: 2B signature low
+- 0E-0F: 2B signature high
+- 10-(10 + 2*number of strings): table of string offsets from the beginning of this file
+- after the table there are the strings themselves, each terminated with `\x00`
+
+The signature is composed of 2B number of strings and 2B checksum in lang_en.bin. Signature in lang_en.bin is zero.
+
+### `lang-check.sh` and `lang-check.py`
+Both do the same, only lang-check.py is newer, i.e. lang-check.sh is not used anymore.
+lang-check.py makes a binary comparison between what's in the dictionary and what's in the binary.
+
+### `lang-clean.sh`
+Removes all language output files from lang folder. That means deleting:
+-  if [ "$1" = "en" ]; then
+  rm_if_exists lang_$1.tmp
+ else
+  rm_if_exists lang_$1.tmp
+  rm_if_exists lang_en_$1.tmp
+  rm_if_exists lang_en_$1.dif
+  rm_if_exists lang_$1.ofs
+  rm_if_exists lang_$1.txt
+ fi
+ rm_if_exists lang_$1_check.dif
+ rm_if_exists lang_$1.bin
+ rm_if_exists lang_$1.dat
+ rm_if_exists lang_$1_1.tmp
+ rm_if_exists lang_$1_2.tmp
+
+### `lang-export.sh`
+Exports PO (gettext) for external translators.
+
+### `lang-import.sh`
+Import from PO
+
+### `progmem.sh`
+
+Examine content of progmem sections (default is progmem1).
+
+Input:
+- $OUTDIR/Firmware.ino.elf
+- $OUTDIR/sketch/*.o (all object files)
+
+Outputs:
+- text.sym     - formated symbol listing of section '.text'
+- $PROGMEM.sym - formated symbol listing of section '.progmemX'
+- $PROGMEM.lss - disassembly listing file
+- $PROGMEM.hex - variables - hex
+- $PROGMEM.chr - variables - char escape
+- $PROGMEM.var - variables - strings
+- $PROGMEM.txt - text data only (not used)
+
+Description of process:
+- check input files
+- remove output files
+- list symbol table of section '.text' from output elf file to text.sym (sorted by address)
+- calculate start and stop address of section '.$PROGMEM'
+- dump $PROGMEM data in hex format, cut disassembly (keep hex data only) into $PROGMEM.lss
+- convert $PROGMEM.lss to $PROGMEM.hex:
+ - replace empty lines with '|' (variables separated by empty lines)
+ - remove address from multiline variables (keep address at first variable line only)
+ - remove '<' and '>:', remove whitespace at end of lines
+ - remove line-endings, replace separator with '\n' (join hex data lines - each line will contain single variable)
+- convert $PROGMEM.hex to $PROGMEM.chr (prepare string data for character check and conversion)
+ - replace first space with tab
+ - replace second and third space with tab and space
+ - replace all remaining spaces with '\x'
+ - replace all tabs with spaces
+- convert $PROGMEM.chr to $PROGMEM.var (convert data to text) - a set of special characters is escaped here including `\x0a`
+
+
+### `textaddr.sh`
+
+Compiles `progmem1.var` and `lang_en.txt` files to `textaddr.txt` file (mapping of progmem addreses to text idenifiers).
+
+Description of process:
+- check if input files exists
+- create sorted list of strings from progmem1.var and lang_en.txt
+- lines from progmem1.var will contain addres (8 chars) and english text
+- lines from lang_en.txt will contain linenumber and english text
+- after sort this will generate pairs of lines (line from progmem1 first)
+- result of sort is compiled with simple script and stored into file textaddr.txt
+
+Input:
+- progmem1.var
+- lang_en.txt
+
+Output:
+- textaddr.txt
+
+
+
+update_lang.sh