Other type of PCB for A9 mini camera.

[ljccitterio]

I am trying to recover the bootloader of this mini camera.

Reading the BK7252 datasheet I found that it is possible to transfer data through its peripheral or SDIO controller. The BK7252 SDIO (secure digital input/output) controller supports master and slave modes. It can operate at clock speeds up to 50 MHz, which is suitable for high-speed data transfers.

The SDIO controller has two modes of operation:

  Master Mode: In this mode, the BK7252 SDIO controller acts as a master device, initiating data transfers and communicating with external devices such as SD cards. In this mode, the BK7252 can read data from or write data to an external SD card.
  Slave Mode: In this mode, the BK7252 SDIO controller acts as a slave device and responds to commands from an external host. In this mode, the BK7252 can be used to communicate with external hosts, such as a computer or other microcontroller.

The SDIO controller supports four data widths: 1-bit, 4-bit, and 8-bit modes. 1-bit mode is the lowest speed mode, while 4-bit mode is the highest speed mode. 8-bit mode is not supported by the BK7252 SDIO controller.

The SDIO controller in the BK7252 has a dedicated DMA (Direct Memory Access) channel. This DMA channel can operate at high speeds without loading the main microcontroller (MCU). This ensures fast and efficient data transfers between the BK7252 SDIO controller and external devices or hosts.

Below is an example of how to configure the SDIO controller in master mode:

void sdio_master_init(void)
{
    uint32_t reg_val;

    /* Enable SDIO clock */
    reg_val = BL_RD_REG(GLB_BASE, GLB_CLK_CFG0);
    reg_val |= (1 << 16);
    BL_WR_REG(GLB_BASE, GLB_CLK_CFG0, reg_val);

    /* Configure SDIO as master */
    reg_val = BL_RD_REG(SDIO_BASE, SDIO_CTRL);
    reg_val &= ~(1 << 0);
    BL_WR_REG(SDIO_BASE, SDIO_CTRL, reg_val);

    /* Configure SDIO clock speed */
    reg_val = BL_RD_REG(SDIO_BASE, SDIO_CLK_CTRL);
    reg_val &= ~(0x7 << 0);
    reg_val |= (0x4 << 0); // 50 MHz
    BL_WR_REG(SDIO_BASE, SDIO_CLK_CTRL, reg_val);

    /* Enable SDIO clock */
    reg_val = BL_RD_REG(SDIO_BASE, SDIO_CLK_CTRL);
    reg_val |= (1 << 8);
    BL_WR_REG(SDIO_BASE, SDIO_CLK_CTRL, reg_val);
}

In this example, the SDIO controller is configured as a master device, with a clock speed of 50 MHz. The SDIO controller is then enabled to start processing data transfers.

Espero te ayude y me ayudes...

[Apache02]

I was able to restore bootloader in SPI flash mode

This is the project i've made for this: https://github.com/Apache02/pico-beken

[ljccitterio]

I was able to restore bootloader in SPI flash mode

This is the project i've made for this: https://github.com/Apache02/pico-beken

Hi...

I'm going to try that method with a NodeMCU ESP8266. I'll have to make some adaptations to LUA or MicroPython.