x87_exception

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Provided by: x87_exception
Class Hierarchy: conf-object → log-object → x87_exception
Interfaces Implemented: log_object, io_memory, pin
Description: This device implements the external hardware needed for MS-DOS compatible handling of x87 exceptions. The circuit is normally part of the south bridge (for example the PIIX4). We have one input pin from the CPU, FERR#, which is asserted by the cpu when CR0.NE is clear + IGNNE# is low + a floating point exception condition is asserted. We have one output pin to the CPU, #IGNNE, which is raised by this device when FERR# is active and the port (normally F0h) is written. IGNNE is cleared when FERR is lowered. The output interrupt pin is raised when FERR, and is cleared by a write to the port. We provide the x87_ferr interface for the cpu to use, and the io-memory interface for the port. This device uses the x87_ignne interface to communicate the IGNNE status, and the simple-interrupt interface to connect to an interrupt controller.

Attributes inherited from class conf-object

attributes, classname, component, iface, name, object_id, queue

Attributes inherited from class log-object

access_count, log_buffer, log_buffer_last, log_buffer_size, log_group_mask, log_groups, log_level, log_type_mask

Attribute List

ferr_status: Optional attribute; read/write access; type: unknown type.
The status of the input ferr line.

ignne_status: Optional attribute; read/write access; type: unknown type.
The status of the output ignne line.

ignne_target: Required attribute; read/write access; type: unknown type.
Object to which the IGNNE line is connected (typically cpu0).

irq_dev: Required attribute; read/write access; type: unknown type.
Target interrupt device (typically a PIC).

irq_level: Required attribute; read/write access; type: unknown type.
Interrupt level (typically 13).

irq_status: Optional attribute; read/write access; type: unknown type.
The status of the output interrupt line.

Commands defined by interface log_object

log, log-group, log-level, log-size, log-type

Commands

info	print information about the device
status	print status of the device

<x87_exception>.info
Synopsis: <x87_exception>.info
Description: Print detailed information about the configuration of the device.

<x87_exception>.status
Synopsis: <x87_exception>.status
Description: Print detailed information about the current status of the device.

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