JiboViteDocs/docs/uart/vectors/validatedmem.md

Validated memory adresses

---

Power Management Controller (PMC)

0x7000E400 — PMC Base Address

Use: The starting point for all Power Management operations.

0x7000E450 — PMC_SCRATCH0

• Use: undefined but i used it as a Data Safe.

• Example: When the USB connection dies, store 4 bytes of data here.

• C Code exampple:

   // Store a 4-byte value from IRAM into the scratch register
   uint32_t leaked_data = *(volatile uint32_t *)0x40001000;
   *(volatile uint32_t *)0x7000E450 = leaked_data;

0x7000E414 — PMC_CNTRL (Reset Control)

• Use: The Reboot Trigger.

• Bit 4: Setting this bit triggers a Warm Reset.

• Example: use this immediately after writing to SCRATCH0 to force Jibo back into RCM mode.

• C Code Implementation:

    // Trigger Warm Reset to return to RCM mode
    *(volatile uint32_t *)0x7000E414 |= (1 << 4);

Timer and Watchdog (TMR/WDT)

These addresses allow us to cut the system’s security features from what i can tell so they don't interfere with the payload.

0x6000501c — TMR_WDT_RESTART

• Use: The Watchdog cut.

• Mechanism: The Tegra K1 has a timer that reboots the device if it doesn't receive a clock signal within a few seconds.

• Example: We write the magic value 0xcafe here in every loop to prevent Jibo from panic-resetting during a dump.

• C Code Implementation:

    while(1) {
        // (reset) 
        *(volatile uint32_t *)0x6000501c = 0xcafe; 
    
        // ... rest of the exploit ...
    }    
    

Internal RAM (IRAM/SRAM)

This is the part where the BootROM is.

0x40000000 — IRAM Base (Start)

• Use: The beginning of the 256KB internal memory.

• Significance: This is where the payload is injected. If u dump from here, u get the "Leftovers" of the boot process (keys, signatures, and config data) from what i could tell.

0x4003FFFF — IRAM End

• Use: The boundary of the volatile memory. (not 100% Sure but pretty certain)

• Constraint: If we try to read past this address, the system will hard-crash because we are hitting undefined memory space.

BootROM Service Functions

The BootROM (at 0x00000000) is read-only memory etched into the silicon. It contains pre-written functions for USB communication that we can "borrow" so we don't have to write a full USB driver from scratch.

0x00003551 — usb_send (Standard)

• Use: Sends a structured data packet over the RCM USB connection.

• Significance: This is the basically the proper way i could get it to talk. It handles some of the USB protocol handshaking automatically.

• Example:

    // Define the function signature based on BootROM
    typedef int (*usb_send_ptr)(void *buffer, unsigned int length);
    usb_send_ptr usb_send = (usb_send_ptr)0x00003551;
    
    //push 64 bytes of IRAM to the PC
    usb_send((void *)0x40000000, 64);

0x000035e5 — usb_send_raw (Bulk)

• Use: A lower-level function that bypasses some of the standard RCM state checks i think.

• Significance: This is how i got those first 16 bytes out. It is open data pushing.

• Example: I used this when the standard usb_send was stalling, as it forces the hardware to dump the buffer to the endpoint immediately.

// Define the raw function pointer typedef void (*usb_send_raw_ptr)(void *buffer, unsigned int length); usb_send_raw_ptr usb_send_raw = (usb_send_raw_ptr)0x000035e5;

//Force dump a 16-byte chunk of IRAM regardless of USB state void dump_raw_chunk() { uint8_t buffer[16]; // Copy the data from a target address (e.g.sstart of IRAM) memcpy(buffer, (void*)0x40000000, 16);

// Push it out. On the PC side
usb_send_raw(buffer, 16);

} ```

Hardware Fuse Registers

The Fuses are permanent oly set at the factory so we cant change these

0x7000F800 — FUSE_BASE

• Use: The starting point for reading the hardware id & status.

• Significance: Reading from here tells us if Jibo is in "Production" mode (Locked) or "Development" mode (Unlocked).

0x7000F800 + 0x60 — Security Config Fuse

• Use: Determines if Secure Boot is active.

• Discovery: In my tests, reading this offset returned random data.

• The Verdict: This confirmed that Jibo is a Secure Boot device. He will only boot software that has been digitally signed by Jibo Inc.’s private keys.

0x7000F900 — FUSE_RESERVED_ODM (The SBK/SSK Area)

• Use: This is where the Secure Boot Key (SBK) usually is.

• The Goal: If we can successfully read this entire block, we might find the AES keys needed to decrypt the Jibo OS files on the EMMC.

The Boot Configuration Table (BCT)

The BCT is a piece of data usually found at the very start of the boot process (and often cached in IRAM).

0x400000f0 — BCT Pointer / Entry Point

• Use: I identified this address in on of the hexdumps i sent on discord.

• Significance: This is where the BootROM hands over control to the next stage of the bootloader.

• The Hack: By targeting our leaker near this address, we can see how the Tegra sets up its memory controllers before it realizes we've hijacked the process.

	void inspect_bct_handoff() {
    // Read the instruction at the BCT entry point
    uint32_t entry_instruction = *(volatile uint32_t *)0x400000f0;
    
    // Often, this is a 'Branch' (B) instruction in ARM hex: 0xEAXXXXXX
    // If 0xEA, we know Jibo is ready run the bootloader
    if ((entry_instruction >> 24) == 0xEA) {
        // Log it for the PC to see
        *(volatile uint32_t *)0x7000E450 = 0xBC7DE4D; // "BCT DEAD" hex flag
    }
}