Differences and connections between sci and SMI?
SMI: System Management Interrupt, System Management interruption, the method of entering SMM, including (but not limited to) power management function, transparent to OS;
After the SMI pin is triggered, the CPU enters the SMM mode and switches to the SMI handler in the BIOS.
SMI pin --> cpu smm mode --> BIOS routine

SCI: System Control interrupt, system control interrupt, defined by ACPI, is an IRQ dedicated to ACPI power management and needs OS support.
After the SCI pin is triggered, the CPU executes a program in the interrupt description table (IDT), which generally points to a driver (ACPI. sys), ACPI driver will notify the relevant driver (acpi ec driver), and then get a code with EC bios, and the code is qxx number in ASL code, then the OS will execute the corresponding ASL code, which is generally method (qxx ).
SCI pin --> OS ACPI driver --> ASL code (Q event) -->? (Refer to BIOS spec requirements)

Contact: both can be used for power management.
Difference: SMI is at the CPU level and can be used in both ACPI and non-ACPI modes; Sci is at the OS level and can only be used in ACPI mode.
Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Differences and connections between sci and SMI? ### Response: SMI: System Management Interrupt, System Management interruption, the method of entering SMM, including (but not limited to) power management function, transparent to OS;
After the SMI pin is triggered, the CPU enters the SMM mode and switches to the SMI handler in the BIOS.
SMI pin --> cpu smm mode --> BIOS routine

SCI: System Control interrupt, system control interrupt, defined by ACPI, is an IRQ dedicated to ACPI power management and needs OS support.
After the SCI pin is triggered, the CPU executes a program in the interrupt description table (IDT), which generally points to a driver (ACPI. sys), ACPI driver will notify the relevant driver (acpi ec driver), and then get a code with EC bios, and the code is qxx number in ASL code, then the OS will execute the corresponding ASL code, which is generally method (qxx ).
SCI pin --> OS ACPI driver --> ASL code (Q event) -->? (Refer to BIOS spec requirements)

Contact: both can be used for power management.
Difference: SMI is at the CPU level and can be used in both ACPI and non-ACPI modes; Sci is at the OS level and can only be used in ACPI mode. 