L4Re Operating System Framework
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L4::Vcon Class Reference

C++ L4 Vcon interface, see Virtual Console for the C interface. More...

#include <vcon>

+ Inheritance diagram for L4::Vcon:
+ Collaboration diagram for L4::Vcon:

Public Member Functions

l4_msgtag_t send (char const *buf, unsigned size, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Send data to this virtual console.
 
long write (char const *buf, unsigned size, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Write data to this virtual console.
 
int read (char *buf, unsigned size, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Read data from this virtual console.
 
int read_with_flags (char *buf, unsigned size, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Read data from this virtual console which also returns flags.
 
l4_msgtag_t set_attr (l4_vcon_attr_t const *attr, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Set the attributes of this virtual console.
 
l4_msgtag_t get_attr (l4_vcon_attr_t *attr, l4_utcb_t *utcb=l4_utcb()) const noexcept
 Get attributes of this virtual console.
 
- Public Member Functions inherited from L4::Icu
l4_msgtag_t bind (unsigned irqnum, L4::Cap< Triggerable > irq, l4_utcb_t *utcb=l4_utcb()) noexcept
 Bind an interrupt line of an interrupt controller to an interrupt object.
 
l4_msgtag_t unbind (unsigned irqnum, L4::Cap< Triggerable > irq, l4_utcb_t *utcb=l4_utcb()) noexcept
 Remove binding of an interrupt line from the interrupt controller object.
 
l4_msgtag_t info (l4_icu_info_t *info, l4_utcb_t *utcb=l4_utcb()) noexcept
 Get information about the ICU features.
 
l4_msgtag_t msi_info (l4_umword_t irqnum, l4_uint64_t source, l4_icu_msi_info_t *msi_info)
 Get MSI info about IRQ.
 
l4_msgtag_t mask (unsigned irqnum, l4_umword_t *label=0, l4_timeout_t to=L4_IPC_NEVER, l4_utcb_t *utcb=l4_utcb()) noexcept
 Mask an IRQ line.
 
l4_msgtag_t set_mode (unsigned irqnum, l4_umword_t mode, l4_utcb_t *utcb=l4_utcb()) noexcept
 Set interrupt mode.
 
- Public Member Functions inherited from L4::Irq_eoi
l4_msgtag_t unmask (unsigned irqnum, l4_umword_t *label=0, l4_timeout_t to=L4_IPC_NEVER, l4_utcb_t *utcb=l4_utcb()) noexcept
 Unmask the given interrupt line.
 

Additional Inherited Members

- Protected Types inherited from L4::Kobject_t< Vcon, Icu, L4_PROTO_LOG >
typedef Vcon Class
 The target interface type (inheriting from Kobject_t)
 
typedef Typeid::Iface< PROTO, Vcon__Iface
 The interface description for the derived class.
 
typedef Typeid::Merge_list< Typeid::Iface_list< __Iface >, typename Base::__Iface_list > __Iface_list
 The list of all RPC interfaces provided directly or through inheritance.
 
- Protected Types inherited from L4::Kobject_t< Icu, Irq_eoi, L4_PROTO_IRQ, Type_info::Demand_t< 1 > >
typedef Icu Class
 The target interface type (inheriting from Kobject_t)
 
typedef Typeid::Iface< PROTO, Icu__Iface
 The interface description for the derived class.
 
typedef Typeid::Merge_list< Typeid::Iface_list< __Iface >, typename Base::__Iface_list > __Iface_list
 The list of all RPC interfaces provided directly or through inheritance.
 
- Protected Member Functions inherited from L4::Kobject_t< Vcon, Icu, L4_PROTO_LOG >
L4::Cap< Classc () const noexcept
 Get the capability to ourselves.
 
- Protected Member Functions inherited from L4::Kobject_t< Icu, Irq_eoi, L4_PROTO_IRQ, Type_info::Demand_t< 1 > >
L4::Cap< Classc () const noexcept
 Get the capability to ourselves.
 
- Static Protected Member Functions inherited from L4::Kobject_t< Vcon, Icu, L4_PROTO_LOG >
static void __check_protocols__ () noexcept
 Helper to check for protocol conflicts.
 
- Static Protected Member Functions inherited from L4::Kobject_t< Icu, Irq_eoi, L4_PROTO_IRQ, Type_info::Demand_t< 1 > >
static void __check_protocols__ () noexcept
 Helper to check for protocol conflicts.
 

Detailed Description

C++ L4 Vcon interface, see Virtual Console for the C interface.

L4::Vcon is a virtual console for simple character-based input and output. The interrupt for read events is provided by the virtual key interrupt.

The Vcon interface inherits from L4::Icu and L4::Irq_eoi for managing the virtual key interrupt which, in contrast to hardware IRQs, implements a limited functionality:

  • Only IRQ line 0 is supported, no MSI vectors.
  • The IRQ is edge-triggered and the IRQ mode cannot be changed.
  • As the IRQ is edge-triggered, it does not have to be explicitly unmasked.

A server implementing the virtual console protocol has a queue for input events. When the first input event is added to the empty queue, the virtual key interrupt is triggered. Further events are added to the queue without generating further interrupts. The queue is emptied when a client reads all queued input events.

Include File
#include <l4/sys/vcon>
C++ Virtual console interface.

See the Virtual Console for the C interface.

Definition at line 56 of file vcon.

Member Function Documentation

◆ get_attr()

l4_msgtag_t L4::Vcon::get_attr ( l4_vcon_attr_t attr,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Get attributes of this virtual console.

Parameters
[out]attrAttribute structure. Contains the attributes after a successful call of this function.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Returns
Syscall return tag.

Definition at line 162 of file vcon.

References l4_vcon_get_attr_u().

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◆ read()

int L4::Vcon::read ( char *  buf,
unsigned  size,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Read data from this virtual console.

Parameters
[out]bufPointer to data buffer.
sizeSize of the data buffer in bytes.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Return values
-L4_EPERMThe Vcon instance requires the L4_CAP_FPAGE_W right on the capability used to invoke this operation and this right is not present.
>sizeMore bytes to read, size bytes are in the buffer buf.
<=sizeNumber of bytes read.
Note
Size must not exceed L4_VCON_READ_SIZE.

Definition at line 109 of file vcon.

References l4_vcon_read_u().

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◆ read_with_flags()

int L4::Vcon::read_with_flags ( char *  buf,
unsigned  size,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Read data from this virtual console which also returns flags.

Parameters
[out]bufPointer to data buffer.
sizeSize of the data buffer in bytes.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Return values
-L4_EPERMThe Vcon instance requires the L4_CAP_FPAGE_W right on the capability used to invoke this operation and this right is not present.
>sizeMore bytes to read, size bytes are in the buffer buf.
<=sizeNumber of bytes read.

If this function returns a positive value the caller can check the L4_VCON_READ_STAT_BREAK flag bit for a break condition. The bytes read can be obtained by masking the return value with L4_VCON_READ_SIZE_MASK.

If a break condition is signaled, it is always the first event in the transmitted content, i.e. all characters supplied by this read call follow the break condition.

Note
Size must not exceed L4_VCON_READ_SIZE.

Definition at line 136 of file vcon.

◆ send()

l4_msgtag_t L4::Vcon::send ( char const *  buf,
unsigned  size,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Send data to this virtual console.

Parameters
bufPointer to the data buffer.
sizeSize of the data buffer in bytes.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Returns
Syscall return tag
Note
Size must not exceed L4_VCON_WRITE_SIZE, a proper value of the size parameter is NOT checked. Also, this function is a send only operation, this means there is no return value except for a failed send operation. Use l4_ipc_error() to check for send errors, do not use l4_error(), as l4_error() will always return an error.

Definition at line 76 of file vcon.

References l4_vcon_send_u().

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◆ set_attr()

l4_msgtag_t L4::Vcon::set_attr ( l4_vcon_attr_t const *  attr,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Set the attributes of this virtual console.

Parameters
attrAttribute structure with the attributes for the virtual console.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Returns
Syscall return tag.

Definition at line 149 of file vcon.

References l4_vcon_set_attr_u().

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◆ write()

long L4::Vcon::write ( char const *  buf,
unsigned  size,
l4_utcb_t utcb = l4_utcb() 
) const
inlinenoexcept

Write data to this virtual console.

Parameters
bufPointer to the data buffer.
sizeSize of the data buffer in bytes.
utcbUTCB to be used for this operation, shall be the UTCB of the calling thread. Defaults to l4_utcb.
Return values
<0Error.
>=0Number of bytes written to the virtual console.

Definition at line 90 of file vcon.

References l4_vcon_write_u().

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The documentation for this class was generated from the following file: