SVC与PendSV 相关

[cisen]

• Cortex M3权威指南
• SVC（Supervisor Call）指令用于产生一个SVC异常。它是用户模式代码中的主进程，用于创造对特权操作系统代码的调用，例如驱动。SVC是用于呼叫操作系统所提供API的正道。用户程序只需知道传递给操作系统的参数，而不必知道各API函数的地址。SVC指令带一个8位的立即数，可以视为是它的参数，被封装在指令自身，如：

  SVC 0x3 ; #调用3 号系统服务

Tock

驱动编号，用于svc订阅

// capsules\src\driver.rs
pub enum NUM {
    // Base
    Alarm                 = 0x00000,
    Console               = 0x00001,
    Led                   = 0x00002,
    Button                = 0x00003,
    Gpio                  = 0x00004,
    Adc                   = 0x00005,
    Dac                   = 0x00006,
    AnalogComparator      = 0x00007,

    // Kernel
    Ipc                   = 0x10000,

    // HW Buses
    Spi                   = 0x20001,
    UsbUser               = 0x20005,
    I2cMasterSlave        = 0x20006,

    // Radio
    BleAdvertising        = 0x30000,
    Ieee802154            = 0x30001,
    Udp                   = 0x30002,

    // Cryptography
    Rng                   = 0x40001,
    Crc                   = 0x40002,
    I2cMaster             = 0x40006,

    // Storage
    AppFlash              = 0x50000,
    NvmStorage            = 0x50001,
    SdCard                = 0x50002,

    // Sensors
    Temperature           = 0x60000,
    Humidity              = 0x60001,
    AmbientLight          = 0x60002,
    NINEDOF               = 0x60004,

    // Sensor ICs
    Tsl2561               = 0x70000,
    Tmp006                = 0x70001,
    Lps25hb               = 0x70004,

    // Other ICs
    Ltc294x               = 0x80000,
    Max17205              = 0x80001,
    Pca9544a              = 0x80002,
    GpioAsync             = 0x80003,
    Nrf51822Serialization = 0x80004,

    // Misc
    Buzzer                = 0x90000,
}