Asking a loader

The commands on this page ask a running Rockchip loader about itself and its flash. None of them writes flash. chipver, storage and reset refuse a block device by name, because a disk runs no loader.

Reading flash geometry

info reports the loader’s flash ID and the size of the flash:

pyrographer info

Device:       2207:350e (loader)
Flash ID:     45 4d 4d 43 20
Flash size:   58.24 GiB (122142720 sectors of 512 bytes)

Reading the chip version

chipver asks the running loader which SoC it is on, and prints the reply as received:

pyrographer chipver

Device:       2207:350e (loader)
Chip version: 16 bytes
  hex         36 37 35 33 00 00 00 00 00 00 00 00 00 00 00 00
  ascii       6753............

This reply is from an RK3576: the SoC’s four ASCII digits byte-reversed, then zeros. An RK3588 answers 38 38 35 33 and twelve bytes of 0xff. chipver sends nothing that changes the device, so you can run it on any board in loader mode.

Every write is gated on this reply. The wrong-loader gate compares the whole reply with the exact bytes a real board returned, and decodes nothing. The two replies above differ after their digits, which is why the gate compares all 16 bytes. A USB product ID names only a family, so the loader is the one authority on which SoC it runs on.

To pin a new SoC, run chipver on a board whose SoC you know. The reply and the SoC together make a new entry in core’s soc module.

Reading the loader’s capabilities

capability asks the loader which features it serves:

pyrographer capability

Device:       2207:350b (maskrom)
Capability:   3f 07 00 00 00 00 00 00
  yes direct LBA
  yes vendor storage
  yes first 4M access
  yes read LBA
  yes read COM log
   no read IDB config
   no read secure mode
  yes new IDB
  yes switch storage

This loader set bits pyrographer has no name for: 10 04 00 00 00 00 00 00

This reply is from the usbplug loader on an RK3588 board. That loader keeps the even bcdUSB flag, so the heading reads maskrom although a loader answered, as Listing devices describes.

The flags are the loader’s own account of itself, and can disagree with what pyrographer implements. A loader that does not set read LBA does not serve the read path, however well the host implements it.

Writing an ID block is gated on new IDB, as Writing the ID block alone describes. Nothing else is gated on these flags. pyrographer reports a bit it has no name for, rather than ignoring it.

Reading the storage medium

storage asks the loader which storage medium is active:

pyrographer storage

Device:       2207:350e (loader)
Storage:      eMMC

A rockusb loader addresses one storage medium at a time, and every LBA is an offset into that medium. On a board with both an eMMC and a SPI NOR, sector 16384 names two different places.

storage reports the medium and leaves it as it is. Like chipver and capability, it sends nothing that changes the device.

Rebooting and reset modes

reset reboots the board:

pyrographer reset

The board is rebooting.

--mode chooses what the board does once it has acknowledged the command, by setting the command’s subcode:

pyrographer reset --mode maskrom

maskrom: this subcode comes from the reference tools, which agree on it, and is untried on a board. It writes no flash. [COMMUNITY]
The board is rebooting into maskrom, where no loader runs. Upload a loader to return it to loader mode.
Run `pyrographer db --loader <file>` to upload a loader.

The three tagged modes use the reference tools’ subcodes, which agree with one another and are untried on a board. None of them writes flash, so none is behind the write gate. Before it sends one of them, reset prints a caution that the mode is untried and writes no flash. Each of these modes ends the session where the verbs cannot follow, and reset says so once the board has acted. reset refuses a mode name outside these four before it opens a device.