--base-id Convention by Coverage Type¶
The --base-id flag of scripts/build-garmin-map.sh sets the numeric Garmin identifier of the compiled map (first of the 8 digits of the .img sub-file name in gmapsupp.img). It must be unique per coverage within the same Garmin family to avoid collisions when installing multiple maps on the same GPS simultaneously.
Automatic resolution
If --base-id is not provided, the script attempts automatic deduction from the first zone (e.g. D038 → 38, cf. scripts/build-garmin-map.sh:580-584). For regions, quadrants and national coverages, no deduction is made — you must pass --base-id explicitly or follow the convention below.
Existing INSEE code ranges¶
| Range | Usage |
|---|---|
01–95, 2A, 2B |
Metropolitan departments |
971–978 |
DOM + Saint-Barthélemy / Saint-Martin |
984 |
TAAF |
986–988 |
Wallis-et-Futuna, French Polynesia, New Caledonia |
R11, R24, R27, R28, R32, R44, R52, R53, R75, R76, R84, R93, R94 |
Regions (INSEE regional codes) |
No INSEE code exists for France quadrants (FRANCE-NO/NE/SO/SE) or for half-France or all of France — these are project-specific subdivisions.
Project convention (proposed)¶
The base-id values are chosen to avoid any collision with INSEE codes (notably DOM-COM in 971–988). The convention has three tiers:
Departments (tier 1–978)¶
→ Direct INSEE code (already automatically deduced by the script).
Metropolitan France:
| Zone | --base-id |
|---|---|
| D001 (Ain) | 1 |
| D038 (Isère) | 38 |
| D075 (Paris) | 75 |
| D02A (Corse-du-Sud) | 201 (INSEE statistical code) |
| D02B (Haute-Corse) | 202 (INSEE statistical code) |
| D095 (Val-d'Oise) | 95 |
Special case: Corsica
Departments 2A and 2B (Corse-du-Sud and Haute-Corse) share the numeric prefix 2, which would cause a Garmin collision if both maps were installed simultaneously on the same GPS. The script therefore applies the INSEE statistical mapping 2A → 201 / 2B → 202 (codes used by INSEE in numeric datasets), guaranteeing their uniqueness.
Overseas (DOM + COM):
| Zone | INSEE code | --base-id |
|---|---|---|
| Guadeloupe | 971 | 971 |
| Martinique | 972 | 972 |
| Guyane | 973 | 973 |
| La Réunion | 974 | 974 |
| Saint-Pierre-et-Miquelon | 975 | 975 |
| Mayotte | 976 | 976 |
| Saint-Barthélemy | 977 | 977 |
| Saint-Martin | 978 | 978 |
| Terres australes et antarctiques françaises (TAAF) | 984 | 984 |
| Wallis-et-Futuna | 986 | 986 |
| French Polynesia | 987 | 987 |
| New Caledonia | 988 | 988 |
Regions (tier 111–194)¶
→ 100 + R-INSEE code: offset of 100 to exit the department range.
| Region | INSEE code | --base-id |
|---|---|---|
| Île-de-France (IDF) | R11 | 111 |
| Centre-Val de Loire (CVL) | R24 | 124 |
| Bourgogne-Franche-Comté (BFC) | R27 | 127 |
| Normandie (NOR) | R28 | 128 |
| Hauts-de-France (HDF) | R32 | 132 |
| Grand Est (GES) | R44 | 144 |
| Pays de la Loire (PDL) | R52 | 152 |
| Bretagne (BRE) | R53 | 153 |
| Nouvelle-Aquitaine (NAQ) | R75 | 175 |
| Occitanie (OCC) | R76 | 176 |
| Auvergne-Rhône-Alpes (ARA) | R84 | 184 |
| Provence-Alpes-Côte d'Azur (PAC) | R93 | 193 |
| Corse (COR) | R94 | 194 |
Quadrants & national (tier 910–999)¶
→ Range 910–999, strictly above regional codes (≤ 194) and below DOM-COM (≥ 971) for quadrants. The national code 999 remains safe as no INSEE territory reaches this value.
| Coverage | --base-id |
Description |
|---|---|---|
FRANCE-NO |
910 |
North-West quadrant |
FRANCE-NE |
920 |
North-East quadrant |
FRANCE-SO |
930 |
South-West quadrant |
FRANCE-SE |
940 |
South-East quadrant |
FRANCE-NORD |
950 |
Northern half (FRANCE-NO + FRANCE-NE) |
FRANCE-SUD |
960 |
Southern half (FRANCE-SO + FRANCE-SE) |
FXX |
999 |
Metropolitan France (complete) |
Potential conflict with DOM-COM
Values 971–988 are reserved for overseas INSEE codes. Never use a --base-id in this range for a project coverage; it is exclusively allocated to the potential publication of DOM-COM maps (department by department).
Defensive variant (optional)¶
To guard against a hypothetical future extension of COM INSEE codes, some projects place non-INSEE coverages in a 9xxx range (4 digits), completely disjoint:
| Coverage | --base-id variant |
|---|---|
FRANCE-NO / NE / SO / SE |
9001 / 9002 / 9003 / 9004 |
FRANCE-NORD / SUD |
9010 / 9020 |
FXX |
9999 |
This variant is more defensive but breaks the visual 3-digit consistency of other codes. The project retains the 910–999 convention, sufficient in practice.
Invocation examples¶
# Department (base-id auto-deduced from D038)
./scripts/build-garmin-map.sh --zones D038 --year 2026 --version v2026.03
# Auvergne-Rhône-Alpes region
./scripts/build-garmin-map.sh --region ARA --base-id 184 --year 2026 --version v2026.03
# South-East France quadrant
./scripts/build-garmin-map.sh --region FRANCE-SE --base-id 940 --year 2026 --version v2026.03
# Complete metropolitan France
./scripts/build-garmin-map.sh --region FXX --base-id 999 --year 2026 --version v2026.03
Installing multiple maps on the same GPS¶
The constraint is simple: two simultaneously installed maps must not share the same base-id. The convention above guarantees that a user can coexist on their GPS:
- An Isère map (
base-id=38) - An Auvergne-Rhône-Alpes map (
base-id=184) - A FRANCE-SE map (
base-id=940) - A DOM Guadeloupe map (
base-id=971)
…without any identifier conflicts.
Comments
Comments are managed by Comentario,
self-hosted at comentario.allfabox.fr. Posting a comment may set a session cookie.