Redmi k90 pro max / poco f8 ultra users commonly run into issues like App Lock Reset & Password Authentication Bugs, especially when dealing with Gboard / Mi Keyboard Auto-Correction Freeze. The stock ROM below is a direct fix for this. This build is made specifically for the Qualcomm SM8850-AC Snapdragon 8 Elite Gen 5 chipset, so confirm your exact model number (e.g. REDMI K90 Pro Max - 25102RKBEC - China, 25102RK69C - Lamborghini Squadra Corse China | POCO F8 Ultra - 25102PCBEG - Global) before downloading.
Whether your Redmi k90 pro max / poco f8 ultra (codename: myron) is soft-bricked, hanging on the boot logo, or you just want to move back to stock MIUI/HyperOS after trying a custom ROM, this guide has what you need — every fastboot and recovery firmware build for this device, reliable download servers, and a full flashing walkthrough.
A quick heads-up before you scroll further: pick the fastboot ROM only if you're comfortable with a full wipe, since it resets the phone completely. If you just need to patch or repair the system without losing your data, the recovery ROM is usually the safer bet.
Device Overview
| Brand | Xiaomi |
|---|
| Device | Redmi k90 pro max / poco f8 ultra |
|---|
| Model Number | REDMI K90 Pro Max - 25102RKBEC - China, 25102RK69C - Lamborghini Squadra Corse China | POCO F8 Ultra - 25102PCBEG - Global |
|---|
| Codename | myron |
|---|
| Chipset | Qualcomm SM8850-AC Snapdragon 8 Elite Gen 5 |
|---|
| OS Version | HyperOS 3 / Android 16 |
|---|
| Storage Variants | 256GB / 512GB / 1TB |
|---|
| RAM Variants | 12GB / 16GB |
|---|
| Approx. Total Size | 11.8 GB |
|---|
| Recommended Tool | Mi Flash Tool |
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Fastboot vs Recovery ROM — Which One Do You Need?
People often download the wrong file the first time, so here's the short version. A fastboot ROM is a complete firmware package meant to be flashed through Mi Flash Tool on a PC — it wipes the device and reinstalls everything from scratch, which makes it the go-to fix for bootloops, dead boot, or a phone that refuses to start. A recovery ROM, on the other hand, is flashed through the phone's built-in Mi Recovery menu and is generally used to update, downgrade, or repair the system without touching your personal data (though a backup is still recommended).
🔹 Fastboot ROM
myron_global_images_OS3.0.302.0.WPMMIXM_20260729.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.302.0.WPMMIXM | 16 | 11.8 GB | 2026-07-29 |
myron_global_images_OS3.0.301.0.WPMMIXM_20260529.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.301.0.WPMMIXM | 16 | 11.8 GB | 2026-05-29 |
myron_global_images_OS3.0.13.0.WPMMIXM_20260318.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.13.0.WPMMIXM | 16 | 11.5 GB | 2026-03-18 |
myron_global_images_OS3.0.12.0.WPMMIXM_20260113.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.12.0.WPMMIXM | 16 | 11.4 GB | 2026-01-13 |
myron_global_images_OS3.0.11.0.WPMMIXM_20251219.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.11.0.WPMMIXM | 16 | 11.4 GB | 2025-12-19 |
myron_global_images_OS3.0.9.0.WPMMIXM_20251205.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.9.0.WPMMIXM | 16 | 11.4 GB | 2025-12-05 |
myron_global_images_OS3.0.8.0.WPMMIXM_20251124.0000.00_16.0_global
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Fastboot ROM | OS3.0.8.0.WPMMIXM | 16 | 11.4 GB | 2025-11-24 |
🔹 Recovery ROM
myron_global-ota_full-OS3.0.302.0.WPMMIXM-user-16.0-83eb2bafc4
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.302.0.WPMMIXM | 16 | 9.0 GB | 2026-08-14 |
myron_global-ota_full-OS3.0.301.0.WPMMIXM-user-16.0-008e85754a
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.301.0.WPMMIXM | 16 | 9.0 GB | 2026-07-01 |
myron_global-ota_full-OS3.0.13.0.WPMMIXM-user-16.0-8a1bb56c94
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.13.0.WPMMIXM | 16 | 8.8 GB | 2026-03-26 |
myron_global-ota_full-OS3.0.12.0.WPMMIXM-user-16.0-28c6570898
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.12.0.WPMMIXM | 16 | 8.8 GB | 2026-01-27 |
myron_global-ota_full-OS3.0.11.0.WPMMIXM-user-16.0-5a7c7ae9d1
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.11.0.WPMMIXM | 16 | 8.8 GB | 2025-12-30 |
myron_global-ota_full-OS3.0.9.0.WPMMIXM-user-16.0-7830dbd924
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.9.0.WPMMIXM | 16 | 8.7 GB | 2025-12-11 |
myron_global-ota_full-OS3.0.8.0.WPMMIXM-user-16.0-7ab77c059d
| Device Name | Codename | Type | MIUI Version | Android OS | Size | Date |
|---|
| Redmi k90 pro max / poco f8 ultra | myron | Recovery ROM | OS3.0.8.0.WPMMIXM | 16 | 8.7 GB | 2025-11-26 |
Got multiple parts to download? Save them all in the same folder first. The archive will fail to extract if any single part is missing.
Tools You'll Need
Get the flashing tool and the right USB driver set up on your PC before you start — in most cases, a failed flash has more to do with a missing driver than with the firmware file.
How to Flash Redmi k90 pro max / poco f8 ultra Using Mi Flash Tool
- Download the fastboot ROM and extract it fully — don't skip extraction, Mi Flash Tool won't read a zipped folder.
- Install Mi Flash Tool from the link above and open it.
- Power off the phone, then hold Volume Down + Power together to boot into Fastboot mode.
- Connect the phone to your PC using a good-quality USB cable — cheap cables are a common cause of connection drops mid-flash.
- In Mi Flash Tool, click "Select" and point it to the extracted firmware folder.
- Once the COM port is detected, hit "Flash" and let it run — don't disconnect the phone during this step.
- The phone will reboot on its own once flashing finishes. First boot can take a few minutes longer than usual, so give it time.
Common Flashing Errors and How to Fix Them
"Auth file needed" — this usually shows up when the connected Mi account isn't authorized for flashing. You'll need an authorized account, or a test-point based flash for unlocked devices.
"COM port not detected" — almost always a driver issue. Install the Qualcomm/MediaTek USB driver from the link above, then put the phone back into EDL or Fastboot mode and try again.
"Flashing failed" partway through — try a different USB cable or port first; if that doesn't help, re-extract the firmware in case a file got corrupted during download.
Frequently Asked Questions
Is this firmware official?
Yes, these are unmodified stock builds pulled directly from Xiaomi's own update servers.
Will flashing delete my data?
Fastboot flashing wipes the device, so back up anything important first. Recovery flashing is less destructive but a backup is still a good idea.
My model number doesn't match exactly — can I still use this?
Always double-check the codename against myron from the table. Flashing the wrong region or variant's firmware can leave the phone unusable.
How to Unlock Bootloader on Redmi k90 pro max / poco f8 ultra
Before you start: Unlocking erases all data on the phone and lowers its security. Back up first.
Steps:
- Log in to your Mi account on the phone.
- Enable Developer options: Settings → About phone → tap OS/MIUI version 7 times.
Bind your account: Settings → Additional settings → Developer options → Mi Unlock status → Add account and device. This needs a SIM card and mobile data turned on.
- Download the Mi Unlock tool on your PC and sign in with the same Mi account.
- Enter Fastboot mode: power off the phone, then hold Power + Volume Down.
- Connect the phone to the PC by USB and click Unlock in the tool.
Good to know:
- Xiaomi usually enforces a waiting period (often 72 to 168 hours). The tool will tell you how long, and the account must stay bound to the phone during that time.
- Newer HyperOS versions have stricter unlock rules in some regions, so check Xiaomi's official unlock page for your region.
- After unlocking, some banking or payment apps may stop working, and Widevine L1 (HD streaming) may be lost.
- Don't flash any custom ROM or tool on a phone until you've found a confirmed guide for that exact model on XDA or the Xiaomi community.
If you hit an error like "Couldn't verify device" or a waiting-time message, let us know in the comments and we'll help.
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