GIET-VM / NIC Driver

The nic_driver.c​ and nic_driver.h​ files define the NIC driver.

This component is a multi-channels, giga-bit Ethernet network controller. It is an external, non replicated peripheral. The number of NIC_RX channels (packet receive) and the number of NIC_TX channels (packet send) are defined by the NB_NIC_CHANNELS parameter in the hard_config.h file. For a given channel index, the NIC_TX channel, and the NIC_RX channel use the same MAC address.

The SEG_NIC_BASE address must be defined in the hard_config.h file.

The addressable registers map is defined here​.

Access Functions

1) unsigned int _nic_get_channel_register( unsigned int channel, unsigned int index )

This function returns the value contained in a channel register.

• channel : channel index
• index : register index

2) void _nic_set_channel_register( unsigned int channel, unsigned int index, unsigned int value )

This function writes a new value in a channel register.

• channel : channel index
• index : register index
• value : written value

3) unsigned int _nic_get_global_register( unsigned int index )

This function returns the value contained in a global register.

• index : register index

4) void _nic_set_global_register( unsigned int index, unsigned int value )

This function writes a new value in a global register.

• index : register index
• value : written value

5) int _nic_global_init( unsigned int channels, unsigned int vis, unsigned int bc_enable, unsigned int bypass_enable )

This function initializes the global registers.

• channels : number of active channels
• vis : bit vector(one bit per active channel)
• bc_enable : broadcast packets accepted if non zero
• bypass_enable : TX -> RX bypass supported if non zero

This function is used only by the boot code, and return always 0.

6) int _nic_channel_start( unsigned int channel, unsigned int mac4, unsigned int mac2 )

This function activates a NIC_TX or NIC_RX channel:

• channel : channel index
• is_rx : boolean (RX type if non zero).
• mac4 : 32 LSB bits of the MAC address.
• mac2 : 16 MSB bits of the MAC address.

It returns always 0.

7) int _nic_channel_stop( unsigned int channel, unsigned int is_rx )

This function desactivates a NIC_TX or NIC_RX channel. It returns always 0.

Interrupt Service Routines

8) void _nic_rx_isr( unsigned int irq_type, unsigned int irq_id, unsigned int channel )

This interrupt Service Routine handles IRQs from a NIC_RX channel. WARNING : Not fully implemented yet : no IRQ acknowledge...

9) void _nic_tx_isr( unsigned int irq_type, unsigned int irq_id, unsigned int channel )

This interrupt Service Routine handles IRQs from a NIC_TX channel. WARNING : Not fully implemented yet : no IRQ acknowledge...