My ASEAN Free GPS Map Project

1. Open GCD in RGN_Tool. At Overrides make sure none is ticked.
2. Save to RGN.

• The above steps are meant for 2 section firmwares. From some other forums I was made to understand that for 3 section firmwares, section 2 and 3 need to be swapped (much like the steps stated below with 3 section firmwares). Ie. The second and third .bin sections need to be saved and loaded according to this particular order: (1) boot.bin, (2) fw1_resources.bin, and (3) fw_all.bin. Nevertheless I am unable to verify this as I do not own (or have tested on) any Nuvi with 3 section firmwares (ie. Nuvi1xxx, Nuvi3xxx series, etc.).

1. Open Sg/My firmware either in GCD (or RGN). At Overrides make sure none is ticked.
2. At fw_all.bin section, select Save. Sg/My firmware fw_all.bin is saved at the specified folder.
3. Open US firmware either in GCD (or RGN).
4. At fw_all.bin section, select Load and select Sg/My fw_all.bin that has been saved earlier.
5. Take note of HWID for boot.bin (or select and copy). At this point HWID for boot.bin (US HWID) is different from HWID for fw_all.bin (Sg/My HWID).
6. At Overrides, tick HWID, and replace it with boot.bin HWID which is the original firmware's HWID (or select and paste).
7. Finally save to RGN.

1. Open Sg/My firmware either in GCD (or RGN). At Overrides make sure none is ticked.
2. At fw_all.bin section, select Save. Sg/My firmware fw_all.bin is saved at the specified folder.
3. At fw1_resources.bin section, select Save. Sg/My firmware fw1_resources.bin is saved at the specified folder.
4. Open US firmware either in GCD (or RGN).
5. At second section (originally fw_all.bin section), select Load and select Sg/My fw1_resources.bin that has been saved earlier.
6. At third section (originally fw1_resources.bin section), select Load and select Sg/My fw_all.bin that has been saved earlier.
7. To summarize (steps 4~6), the sections order should be as follows: (1) boot.bin (US firmware, untouched), (2) fw1_resources.bin (Sg/My firmware), and (3) fw_all.bin (Sg/My firmware).
8. Take note of HWID for boot.bin (or select and copy). At this point HWID for boot.bin (US HWID) is different from HWID for fw_all.bin (Sg/My HWID).
9. At Overrides, tick HWID, and replace it with boot.bin HWID which is the original firmware's HWID (or select and paste).
10. Finally save to RGN.

• Always use latest version of RGN_Tool available here: http://turboccc.wikispaces.com/RGN_Tool
• The idea of creating patched RGN is to retain boot.bin section of original firmware, and to patch other section(s) with another firmware.
• To verify that correct RGN is generated, open patched RGN in RGN_Tool. Untick Overrides (if it's ticked). Make sure HWID for both boot.bin and fw_all.bin are similar and correspond to original firmware's HWID. Also make sure SW version for boot.bin corresponds to original firmware version, while SW version for fw_all.bin corresponds to the other firmware version (so you know they don't get accidentally mixed up).
• Patched RGN may not work with some HWID (may result in "System Software Missing" error, and the remedy is to revert to normal RGN generated from original GCD).
• Credits to TurboCCC for this awesome tool.

Albert_Chong wrote:RGN_tools v028 is UP. http://turboccc.wikispaces.com/RGN_Tool
now correcting the checksum, in diagnostic mode, the ROM an RAM checking will be passed now.
My friend get it done with using this tools get the RGN file and get it done convert Nuvi 3790 us firmware to SgMy firmware, and junction view and lane assist work perfert.
for my Nuvi 1300 US bought from ebay US$40, Used, also get it done convert to use Nuvi 1350 SgMy firmware, but only firmware version v2.40 work with Sgmy junction view and lane assist, v2.50 and v2.60 although get it done converted, but Junction view still no see. my another friend also get it done flashed his taiwan Nuvi 255W S4 board use latest SgMy v3.10, junction view working, if S4 board, please use original Taiwan boot loader + sgmy firmware v3.10, if not, white screen will be happened.
Just use this RGN_tools.

Official disclaimers:
Do this at your own risks!
Do not flash any FW if you are getting weird errors!

jeuda wrote:It worked! Thanks a million.