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FAQ

Whether you are a beginner or an experienced developer, you may encounter some questions or difficulties when using the development board. We hope to provide you with answers to common questions about the LuckFox Pico series development boards through this FAQ document, making it easier for you to develop and experiment.

1. Memory Allocation​

After logging into the development board, users often check system resources such as RAM and storage. Attentive users may notice differences between the observed parameters and the specifications listed on the official website. The following analysis is based on debugging the serial port logs:

  1. Memory Allocation

    [    1.164716] Memory: 88280K/131072K available (3683K kernel code, 389K rwdata, 1840K rodata, 180K init, 111K bss, 10024K reserved, 32768K cma-reserved)
    • Total memory: 131072K, which equals 131072K ÷ 1024 = 128MB.
    • Available memory: 88280K, representing the remaining usable memory in the system, calculated as 88280K ÷ 1024 = 86.2MB.
    • Reserved memory: 10024K, unavailable for user space.
    • CMA-reserved memory: 32768K, dedicated for the display.

  2. Storage Space

    [    1.291355] spi-nand spi2.0: Winbond SPI NAND was found.
    [    1.291455] spi-nand spi2.0: 256 MiB, block size: 128 KiB, page size: 2048, OOB size: 128
    [    1.292644] 3 cmdlinepart partitions found on MTD device spi-nand0
    [    1.292675] Creating 3 MTD partitions on "spi-nand0":
    [    1.292692] 0x000000400000-0x000000800000 : "uboot"
    [    1.295177] 0x000000800000-0x000001400000 : "boot"
    [    1.297493] 0x000002000000-0x00000ff60000 : "rootfs"
    • The SPI NAND Flash has a capacity of 256 MiB.
      • uboot: 4 MiB (0x000000400000-0x000000800000).
      • boot: 12 MiB (0x000000800000-0x000001400000).
      • rootfs: 223 MiB (0x000002000000-0x00000ff60000).
    [    1.977977] ubi0: attached mtd2 (name "rootfs", size 223 MiB)
    [    2.058270] UBIFS (ubi0:0): FS size: 219922432 bytes (209 MiB, 1732 LEBs), max 8456 LEBs, journal size 9023488 bytes (8 MiB, 72 LEBs)
    • fter mounting the file system, the reported size is 209 MiB.

Summary

The UBIFS file system uses physical erase blocks (PEB) and logical erase blocks (LEB), with features like journaling, recovery data, and wear leveling consuming additional storage. As a result, although the file system size is listed as 209 MiB, the actual usable space may be smaller.

Specifically:

  • 209 MiB converts to 219.15 MB (209 × 1.048576).
  • After accounting for the consumed space, the actual usable space is approximately 193 MB.

2. Overview of Test Points on Lyra / Lyra B​

SIM7600G-H