KNULLI microSD Roles and Formats: TF1, Optional TF2, ext4 vs exFAT

Destructive Warning: Stop Before Formatting

Formatting erases all data on the selected storage. Before using any KNULLI Format a Disk action, verify a separate backup using the KNULLI backup guide, identify the intended external card by both its label and reported capacity, and cancel if anything is ambiguous.

Never format the TF1/system card to prepare TF2. Never use formatting as a diagnostic step. Do not format, repair, initialize, repartition, clone, or change UUIDs as part of this guide.

Short Answer

KNULLI gives the two card roles different jobs:

TF1 is the system card. For Scarab 20260511 on RG CubeXX, the official KNULLI image creates the first-card layout.
TF2 is conditional and optional. If your device physically has a second slot and KNULLI exposes it, that card can replace TF1’s SHARE/userdata storage. It is not an additive second game library.
Current KNULLI documentation lists ext4 and exFAT for data storage. ext4 is not directly accessible from Windows or macOS; exFAT is compatible with those hosts. This is a host-access tradeoff, not evidence that one is safer, faster, or universally better.

This guide does not tell you to format a card or recommend a capacity, brand, speed class, or health test. Its endpoint is narrower: identify your release and intended card role, understand the documented format tradeoff, preserve your data, and continue with the correct dedicated guide.

For the wider RG CubeXX guide index, see the KNULLI troubleshooting and setup hub.

Scope and Evidence

Version and evidence box

Primary device scope: RG CubeXX using the named H700 Scarab image

Current release scope: Scarab 20260511

Legacy releases: Firefly 20241204 and Gladiator II 20250813 are listed only to mark their storage details as unverified here

Evidence: official KNULLI documentation and the tagged Scarab release, plus standards and host-OS documentation for narrow terminology

Testing status: documentation-based; no owner hands-on result is claimed

Endpoint: role and tradeoff understood, data preserved, correct handoff chosen

SOURCE-CONFIRMED: KNULLI publishes the Scarab RG CubeXX image knulli-h700-rg-cubexx-scarab-20260511.img.gz. The Scarab release also documents a major partition-table change affecting the first card, while stating that this first-card change does not affect SD2.

UNCONFIRMED: This evidence does not establish a universal RG CubeXX or H700 card-capacity limit, a preferred card brand, a speed or endurance requirement, or a universal slot count across H700 devices.

Release Matrix

Do not merge these rows or apply current documentation backward to older releases.

Release	What is established	What remains unconfirmed	Safe action
Firefly `20241204`	The release name and date identify a legacy KNULLI generation	TF1 partition layout, TF2 behavior, formatter choices, migration behavior, and capacity support were not verified by the evidence gate	Do not use this article as Firefly setup or formatting instructions; consult release-specific documentation after preserving data
Gladiator II `20250813`	It predates Scarab	Exact TF1/TF2 layout, formatter choices, migration behavior, and capacity support were not verified for this release	Do not backport current KNULLI documentation as though it were tagged Gladiator II behavior
Scarab `20260511`	Official release provides the named RG CubeXX image; changes the first-card partition table; says SD2 is not affected by that change	No universal maximum capacity, brand recommendation, or complete migration guarantee	Use the Scarab facts only within this release scope; use the install and backup handoffs below
Current KNULLI documentation	A second card can replace primary `SHARE` on devices that support it; documented data-storage choices include ext4 and exFAT	It does not prove identical behavior on Firefly or Gladiator II	Treat these as current, conditional instructions rather than historical guarantees

Scarab’s SD2 migration warning

The Scarab release says legacy userdata migration for SD2 is automatic and recommends a fresh setup if problems occur. That is a release warning, not proof that every file migrates successfully.

Back up first. Do not use this article as a migration procedure, and do not assume folder appearance proves that old data was copied. The official KNULLI major-update guide is the release-specific reference; the backup article owns selective backup and restore boundaries.

TF1 vs Optional TF2

TF1: the imaged system card

SOURCE-CONFIRMED: Scarab installation uses the device-specific image to create the system-card layout. The official Scarab warning describes a major first-card partition-table change.

That means TF1 is not a blank data card to arrange manually. Do not change its partitions or format it to prepare a second card. For official image selection, safe flashing, Windows format-prompt handling, and first boot, use How to Install KNULLI on RG CubeXX.

After imaging, decline Windows prompts to initialize, format, fix, or make an unfamiliar partition usable. A KNULLI image can create a layout that Windows does not present as one ordinary removable drive. Windows not showing every partition is not permission to repair the card.

TF2: an alternative active SHARE/userdata store

Use this wording carefully:

If your device physically has a second slot and KNULLI exposes it, a second card can be selected instead of the primary card’s SHARE storage.

Current KNULLI documentation says SD1 and SD2 cannot both act as game storage at the same time. The optional second card is therefore an alternative active store, not an additive library joined to TF1.

This distinction matters because seeing a card or seeing KNULLI-created folders does not prove it actively backs logical /userdata. The second-SD storage guide owns selection, persisted UUID behavior, the required restart, fallback to Internal, and active-store verification.

UNCONFIRMED: The research did not establish a product-specific slot-count statement from official Anbernic material. Do not generalize a physical label, slot count, or device-node name from RG CubeXX to every H700 handheld.

ext4 vs exFAT in Current KNULLI Documentation

The following comparison describes only the current KNULLI formatter choices documented for data storage. It is not a recommendation to format a card.

Choice	Documented host-access behavior	Appropriate question	What you must not infer
ext4	Not directly accessible from Windows or macOS	Do you intend to keep the data in a Linux/KNULLI-oriented filesystem without direct Windows/macOS card access?	That ext4 is safer, faster, healthier, or universally preferred
exFAT	Compatible with Windows and macOS	Do you need to shut down, remove the data card, and access it directly from a supported host?	That exFAT is always best, that every card arrives ready, or that host visibility proves device support

Choose between them only after deciding the role and host-access requirement. Do not install a third-party filesystem driver for this workflow. Do not infer support for FAT32, NTFS, btrfs, APFS, or another filesystem; this evidence gate did not establish those as KNULLI TF2 choices.

Folder creation is not migration proof

Current KNULLI documentation says its documented storage setup can populate the data storage with the folders and files normally used under userdata/SHARE.

That observation proves only that initialization created a layout. It does not prove that:

the card is the active /userdata store;
existing saves, BIOS files, games, media, or settings migrated;
every copied file is complete;
the card’s advertised capacity is authentic; or
the card will remain healthy.

Capacity Standards Are Not Device Support

FACT: SD, SDHC, SDXC, and SDUC are SD-standard capacity families. Their family limits classify the card standard.

They do not establish that RG CubeXX, another H700 device, a reader, a KNULLI release, or a particular filesystem supports a given capacity. Do not convert “SDXC” or another standards label into a handheld compatibility claim.

This article therefore gives no minimum, maximum, or “best” capacity. It also gives no:

brand ranking;
speed-class, endurance, price, or allocation-unit recommendation;
claim that a larger card works;
inference from image download size or expanded filesystem size;
counterfeit verdict;
H2testw, F3, SMART, or destructive capacity-test procedure.

A displayed capacity is an observation only. A successful boot, file copy, visible drive letter, or one error is not proof of authenticity, full usable capacity, long-term health, or device-wide compatibility.

Keep the receipt and packaging, compare reported capacity with the seller or manufacturer’s specification, and preserve a backup before troubleshooting. This still does not turn a single observation into a health certificate.

Non-Destructive Role and Format Checklist

This checklist intentionally stops before imaging, formatting, active-storage selection, migration, or repair.

Record the release. Note the exact KNULLI release name and date. Do not treat Firefly, Gladiator II, and Scarab as interchangeable.
Record the model. For Scarab on RG CubeXX, confirm that the official asset is knulli-h700-rg-cubexx-scarab-20260511.img.gz.
Define the intended role. Write down either “TF1 system card” or “conditional TF2 alternative SHARE/userdata card.” Do not call TF2 an additive library.
Record identity observations. Note the card’s visible label and reported capacity. These help distinguish targets but do not prove UUID internals, authenticity, health, or compatibility.
Preserve the source. Keep any existing card untouched and verify a separate backup before a risky operation. Do not assume that one unverified copy is complete.
Use the installation handoff for TF1. Follow the RG CubeXX Scarab installation guide for imaging and first boot. This article does not duplicate it.
Decline host interference after imaging. Reject Windows offers to initialize, format, fix, or repair unfamiliar KNULLI partitions.
Power off fully before handling cards. Do not hot-swap either card. This guide authorizes no insert/remove action while powered.
Observe only. After a documented setup, you may note whether KNULLI shows the expected storage label and whether the expected data folders exist. Do not edit partitions or run a capacity-writing test.
Use the active-storage handoff. If the question is whether TF2 remains selected and backs /userdata, continue with the second-SD selection guide.
Stop on ambiguity. If the physical card, role, release, label, or reported capacity does not match your record, stop. Do not guess and do not format.

What These Observations Prove—and What They Do Not

Observation	Narrow conclusion	Not proven
Exact Scarab RG CubeXX asset name matches	Release asset and intended model are aligned	Card capacity support, written-image integrity, or card health
TF1 boots once	That boot reached the observed point in that session	Authenticity, longevity, full capacity, or future reliability
KNULLI displays a storage label and capacity	The frontend reported those values	The card’s hidden identity, advertised capacity accuracy, or active `/userdata` mount
KNULLI-created folders appear	A layout was initialized	Data migration, active-store persistence, or file completeness
Windows or macOS can read an exFAT card	The host can access that filesystem in the observed setup	KNULLI compatibility across releases or long-term reliability
Windows or macOS cannot directly read ext4	This matches the documented host-access limitation	A damaged card or a need to install a third-party driver

The checklist can support only two conclusions: your release/asset/card-role record is internally consistent, and you understand the documented ext4/exFAT host-access tradeoff. It is not a capacity test, health test, migration proof, or active-storage proof.

Stop and Use the Correct Handoff

Stop immediately if you cannot identify the target card, lack a verified backup of irreplaceable data, cannot confirm the release, or are unsure whether the device has and exposes a second slot.

Use these boundaries:

Need to image TF1 or complete first boot? Use the Scarab installation guide.
Need to preserve saves and personal data? Use the backup guide.
TF2 is visible but not active, reverts after restart, or capacity looks wrong? Use the second-SD storage guide.
Using Firefly or Gladiator II? Stop. This article does not verify those releases’ card layouts, format choices, migration, or capacity support.
Suspect a counterfeit or failing card? Preserve data and evidence. This article does not provide a verdict or authorize destructive tests.

Do not hot-swap, accept a host repair prompt, change partitions, clone a card as a fix, edit UUIDs, install filesystem drivers, or run a full-capacity write test.

Version Differences

Firefly `20241204`

UNCONFIRMED: This evidence gate did not verify Firefly’s TF1 layout, TF2 behavior, formatting choices, migration behavior, or capacity support. No Firefly card instructions are provided here.

Gladiator II `20250813`

UNCONFIRMED: Current KNULLI documentation must not be treated as a tagged Gladiator II storage specification. Do not backport the Scarab partition warning or current ext4/exFAT workflow to this release.

Scarab `20260511`

SOURCE-CONFIRMED: Scarab provides the named H700 RG CubeXX image, changes the partition table of the first card, and says this first-card change does not affect SD2. Its SD2 legacy-userdata migration statement is release-specific and is not a completeness guarantee.

RG CubeXX and shared H700 limits

SOURCE-CONFIRMED: A Scarab image exists specifically for H700 RG CubeXX.

UNCONFIRMED: That does not establish identical slot layouts, physical labels, device nodes, maximum capacities, or filesystem behavior for every H700 handheld.

What this guide does not cover

This guide explains TF1/TF2 roles and filesystem tradeoffs before a change. It does not format a card, flash KNULLI, select active userdata, migrate files, repair Windows networking, troubleshoot game discovery, or recommend a universal microSD model. Use the dedicated install, second-SD, transfer, and backup guides for those procedures.

Screenshot, Privacy, and Evidence Limits

Screenshots are optional. Do not show Windows Disk Management, drive letters, serial numbers, unredacted volume labels, order pages, receipts, usernames, network hosts, IP addresses, ROM names, save names, or personal folder paths.

If a KNULLI UI image is necessary:

crop it to the relevant storage or formatter control;
redact device identifiers and personal labels;
caption the exact KNULLI release;
do not use it as evidence of universal capacity, health, migration, or compatibility.

A screenshot proves only what was visible at that moment. It cannot prove the underlying UUID, active mount, persistence after restart, or long-term card condition.

FAQ

Does RG CubeXX support a specific maximum microSD capacity?

This evidence does not establish one. SDHC, SDXC, and SDUC family limits are standards classifications, not RG CubeXX support specifications.

What size or brand should I buy?

This guide makes no capacity, brand, speed, endurance, or price recommendation. No qualifying comparison was established for those claims.

Is TF2 extra storage added to TF1?

Not according to current KNULLI documentation. On supported devices, the second card replaces the primary SHARE/userdata store when selected; both are not combined as simultaneous game storage.

Should I choose ext4 or exFAT?

Choose based only on the documented host-access requirement. ext4 is not directly accessible from Windows or macOS, while exFAT is compatible with those hosts. This article does not claim either is faster, safer, or universally better.

Can I format TF1 to create TF2 storage?

No. TF1 is the imaged system card. Do not format it to prepare an optional second card.

Do new folders prove TF2 is active?

No. Folder creation indicates initialization. Use the dedicated second-SD guide to verify the selected and active storage after the required restart.

Does one successful boot prove the card is genuine and healthy?

No. It proves only that the observed boot reached that point. It does not prove authentic advertised capacity, full-card integrity, longevity, or future reliability.

Should Windows repair a KNULLI card it cannot fully read?

No. Decline initialize, format, fix, and repair prompts after imaging. Do not change KNULLI partitions merely to make every volume visible in Windows.

Can I use this guide for Firefly or Gladiator II?

Only for the warning that their behavior remains unverified here. It provides no Firefly or Gladiator II layout, formatting, migration, or capacity instructions.

Destructive Warning: Stop Before Formatting