pxe_call.c File Reference

PXE API entry point. More...

#include <ipxe/uaccess.h>
#include <ipxe/init.h>
#include <ipxe/profile.h>
#include <ipxe/netdevice.h>
#include <rmsetjmp.h>
#include <registers.h>
#include <biosint.h>
#include <pxe.h>
#include <pxe_call.h>

Go to the source code of this file.

Macros
#define	EINFO_EPXENBP
#define	EPXENBP(status)   EPLATFORM ( EINFO_EPXENBP, status )
#define	pxe_int_1a_vector   __use_text16 ( pxe_int_1a_vector )
#define	_text16_memsz   ABS_VALUE ( _text16_memsz )
#define	_data16_memsz   ABS_VALUE ( _data16_memsz )

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
struct segoff	__text16 (pxe_int_1a_vector)
	Vector for chaining INT 1A. More...
void	pxe_int_1a (void)
	INT 1A handler. More...
size_t	ABS_SYMBOL (_text16_memsz)
	Real-mode code segment size. More...
size_t	ABS_SYMBOL (_data16_memsz)
	Real-mode data segment size. More...
static PXENV_EXIT_t	pxenv_unknown (struct s_PXENV_UNKNOWN *pxenv_unknown)
	Handle an unknown PXE API call. More...
static struct pxe_api_call *	find_pxe_api_call (uint16_t opcode)
	Locate PXE API call. More...
static struct profiler *	pxe_api_profiler (unsigned int opcode)
	Determine applicable profiler (for debugging) More...
__asmcall void	pxe_api_call (struct i386_all_regs *ix86)
	Dispatch PXE API call. More...
int	pxe_api_call_weak (struct i386_all_regs *ix86)
	Dispatch weak PXE API call with PXE stack available. More...
__asmcall void	pxe_loader_call (struct i386_all_regs *ix86)
	Dispatch PXE loader call. More...
static uint8_t	pxe_checksum (void *data, size_t size)
	Calculate byte checksum as used by PXE. More...
static void	pxe_init_structures (void)
	Initialise !PXE and PXENV+ structures. More...
struct init_fn pxe_init_fn	__init_fn (INIT_NORMAL)
	PXE structure initialiser. More...
void	pxe_activate (struct net_device *netdev)
	Activate PXE stack. More...
int	pxe_deactivate (void)
	Deactivate PXE stack. More...
int	pxe_start_nbp (void)
	Start PXE NBP at 0000:7c00. More...
static int	pxe_notify (struct net_device *netdev, void *priv __unused)
	Notify BIOS of existence of network device. More...
	REQUIRING_SYMBOL (pxe_api_call)
	REQUIRE_OBJECT (pxe_preboot)
	REQUIRE_OBJECT (pxe_undi)
	REQUIRE_OBJECT (pxe_udp)
	REQUIRE_OBJECT (pxe_tftp)
	REQUIRE_OBJECT (pxe_file)

Variables
static int	int_1a_hooked = 0
	INT 1A hooked flag. More...
static struct profiler pxe_api_tx_profiler	__profiler
	PXENV_UNDI_TRANSMIT API call profiler. More...
struct pxe_api_call pxenv_unknown_api	__pxe_api_call
	Unknown PXE API call list. More...
rmjmp_buf	pxe_restart_nbp
	Jump buffer for PXENV_RESTART_TFTP. More...
struct net_driver pxe_driver	__net_driver
	PXE BIOS notification driver. More...

Detailed Description

PXE API entry point.

Definition in file pxe_call.c.

Macro Definition Documentation

EINFO_EPXENBP

#define EINFO_EPXENBP

Value:

__einfo_uniqify ( EINFO_EPLATFORM, 0x01,                        \
                          "External PXE NBP error" )

Definition at line 42 of file pxe_call.c.

EPXENBP

#define EPXENBP

(

status

)

EPLATFORM ( EINFO_EPXENBP, status )

Definition at line 45 of file pxe_call.c.

pxe_int_1a_vector

#define pxe_int_1a_vector   __use_text16 ( pxe_int_1a_vector )

Definition at line 49 of file pxe_call.c.

_text16_memsz

#define _text16_memsz   ABS_VALUE ( _text16_memsz )

Definition at line 59 of file pxe_call.c.

_data16_memsz

#define _data16_memsz   ABS_VALUE ( _data16_memsz )

Definition at line 63 of file pxe_call.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

__text16()

struct segoff __text16

(

pxe_int_1a_vector

)

Vector for chaining INT 1A.

pxe_int_1a()

void pxe_int_1a

(

void

)

INT 1A handler.

Referenced by pxe_activate(), and pxe_deactivate().

ABS_SYMBOL() [1/2]

size_t ABS_SYMBOL

(

_text16_memsz

)

Real-mode code segment size.

ABS_SYMBOL() [2/2]

size_t ABS_SYMBOL

(

_data16_memsz

)

Real-mode data segment size.

pxenv_unknown()

static PXENV_EXIT_t pxenv_unknown ( struct s_PXENV_UNKNOWN *  pxenv_unknown )

static

Handle an unknown PXE API call.

Parameters

pxenv_unknown

Pointer to a struct s_PXENV_UNKNOWN

Return values

PXENV_EXIT_FAILURE

Always

Exceptions

PXENV_STATUS_UNSUPPORTED

Always

Definition at line 92 of file pxe_call.c.

                                                                            {
        pxenv_unknown->Status = PXENV_STATUS_UNSUPPORTED;
        return PXENV_EXIT_FAILURE;
}

References PXENV_EXIT_FAILURE, and PXENV_STATUS_UNSUPPORTED.

find_pxe_api_call()

static struct pxe_api_call* find_pxe_api_call ( uint16_t  opcode )

static

Locate PXE API call.

Parameters

opcode

Opcode

Return values

call	PXE API call, or NULL

Definition at line 107 of file pxe_call.c.

                                                                   {
        struct pxe_api_call *call;

        for_each_table_entry ( call, PXE_API_CALLS ) {
                if ( call->opcode == opcode )
                        return call;
        }
        return NULL;
}

References for_each_table_entry, NULL, opcode, pxe_api_call::opcode, and PXE_API_CALLS.

Referenced by pxe_api_call().

pxe_api_profiler()

static struct profiler* pxe_api_profiler ( unsigned int  opcode )

static

Determine applicable profiler (for debugging)

Parameters

opcode

PXE opcode

Return values

profiler

Profiler

Definition at line 123 of file pxe_call.c.

                                                                  {

        /* Determine applicable profiler */
        switch ( opcode ) {
        case PXENV_UNDI_TRANSMIT:
                return &pxe_api_tx_profiler;
        case PXENV_UNDI_ISR:
                return &pxe_api_isr_profiler;
        case PXENV_UNKNOWN:
                return &pxe_api_unknown_profiler;
        default:
                return &pxe_api_misc_profiler;
        }
}

References opcode, PXENV_UNDI_ISR, PXENV_UNDI_TRANSMIT, and PXENV_UNKNOWN.

Referenced by pxe_api_call().

pxe_api_call()

__asmcall void pxe_api_call

(

struct i386_all_regs *

ix86

)

Dispatch PXE API call.

Parameters

bx	PXE opcode
es:di	Address of PXE parameter block

Return values

ax	PXE exit code

Definition at line 145 of file pxe_call.c.

                                                           {
        uint16_t opcode = ix86->regs.bx;
        struct profiler *profiler = pxe_api_profiler ( opcode );
        union u_PXENV_ANY *params =
                real_to_virt ( ix86->segs.es, ix86->regs.di );
        struct pxe_api_call *call;
        PXENV_EXIT_t ret;

        /* Start profiling */
        profile_start ( profiler );

        /* Locate API call */
        call = find_pxe_api_call ( opcode );
        if ( ! call ) {
                DBGC ( &pxe_netdev, "PXENV_UNKNOWN_%04x\n", opcode );
                call = &pxenv_unknown_api;
        }

        /* Set default status in case child routine fails to do so */
        params->Status = PXENV_STATUS_FAILURE;

        /* Hand off to relevant API routine */
        ret = call->entry ( params );

        /* Return exit code in %ax */
        ix86->regs.ax = ret;

        /* Stop profiling, if applicable */
        profile_stop ( profiler );
}

References i386_regs::ax, i386_regs::bx, DBGC, i386_regs::di, pxe_api_call::entry, i386_seg_regs::es, find_pxe_api_call(), opcode, profile_start(), profile_stop(), pxe_api_profiler(), pxe_netdev, PXENV_STATUS_FAILURE, real_to_virt(), i386_all_regs::regs, i386_all_regs::segs, and u_PXENV_ANY::Status.

Referenced by pxe_api_call_weak().

pxe_api_call_weak()

int pxe_api_call_weak

(

struct i386_all_regs *

ix86

)

Dispatch weak PXE API call with PXE stack available.

Parameters

ix86	Registers for PXE call

Return values

present

Zero (PXE stack present)

Definition at line 182 of file pxe_call.c.

                                                     {
        pxe_api_call ( ix86 );
        return 0;
}

References pxe_api_call().

pxe_loader_call()

__asmcall void pxe_loader_call

(

struct i386_all_regs *

ix86

)

Dispatch PXE loader call.

Parameters

es:di

Address of PXE parameter block

Return values

ax	PXE exit code

Definition at line 193 of file pxe_call.c.

                                                              {
        struct s_UNDI_LOADER *params =
                real_to_virt ( ix86->segs.es, ix86->regs.di );
        PXENV_EXIT_t ret;

        /* Fill in ROM segment address */
        ppxe.UNDIROMID.segment = ix86->segs.ds;

        /* Set default status in case child routine fails to do so */
        params->Status = PXENV_STATUS_FAILURE;

        /* Call UNDI loader */
        ret = undi_loader ( params );

        /* Return exit code in %ax */
        ix86->regs.ax = ret;
}

References i386_regs::ax, i386_regs::di, i386_seg_regs::ds, i386_seg_regs::es, ppxe, PXENV_STATUS_FAILURE, real_to_virt(), i386_all_regs::regs, i386_all_regs::segs, s_UNDI_LOADER::Status, and undi_loader.

pxe_checksum()

static uint8_t pxe_checksum ( void *  data, size_t  size  )

static

Calculate byte checksum as used by PXE.

Parameters

data	Data
size	Length of data

Return values

sum

Checksum

Definition at line 218 of file pxe_call.c.

                                                        {
        uint8_t *bytes = data;
        uint8_t sum = 0;

        while ( size-- ) {
                sum += *bytes++;
        }
        return sum;
}

References bytes, data, and size.

Referenced by pxe_init_structures().

pxe_init_structures()

static void pxe_init_structures ( void  )

static

Initialise !PXE and PXENV+ structures.

Definition at line 232 of file pxe_call.c.

                                         {
        uint32_t rm_cs_phys = ( rm_cs << 4 );
        uint32_t rm_ds_phys = ( rm_ds << 4 );

        /* Fill in missing segment fields */
        ppxe.EntryPointSP.segment = rm_cs;
        ppxe.EntryPointESP.segment = rm_cs;
        ppxe.Stack.segment_address = rm_ds;
        ppxe.Stack.Physical_address = rm_ds_phys;
        ppxe.UNDIData.segment_address = rm_ds;
        ppxe.UNDIData.Physical_address = rm_ds_phys;
        ppxe.UNDICode.segment_address = rm_cs;
        ppxe.UNDICode.Physical_address = rm_cs_phys;
        ppxe.UNDICodeWrite.segment_address = rm_cs;
        ppxe.UNDICodeWrite.Physical_address = rm_cs_phys;
        pxenv.RMEntry.segment = rm_cs;
        pxenv.StackSeg = rm_ds;
        pxenv.UNDIDataSeg = rm_ds;
        pxenv.UNDICodeSeg = rm_cs;
        pxenv.PXEPtr.segment = rm_cs;

        /* Update checksums */
        ppxe.StructCksum -= pxe_checksum ( &ppxe, sizeof ( ppxe ) );
        pxenv.Checksum -= pxe_checksum ( &pxenv, sizeof ( pxenv ) );
}

References ppxe, pxe_checksum(), pxenv, rm_cs, and rm_ds.

__init_fn()

struct init_fn pxe_init_fn __init_fn

(

INIT_NORMAL

)

PXE structure initialiser.

pxe_activate()

void pxe_activate

(

struct net_device *

netdev

)

Activate PXE stack.

Parameters

netdev

Net device to use as PXE net device

Definition at line 269 of file pxe_call.c.

                                                {
        uint32_t discard_a;
        uint32_t discard_b;
        uint32_t discard_d;

        /* Ensure INT 1A is hooked */
        if ( ! int_1a_hooked ) {
                hook_bios_interrupt ( 0x1a, ( intptr_t ) pxe_int_1a,
                                      &pxe_int_1a_vector );
                devices_get();
                int_1a_hooked = 1;
        }

        /* Set PXE network device */
        pxe_set_netdev ( netdev );

        /* Notify BIOS of installation */
        __asm__ __volatile__ ( REAL_CODE ( "pushw %%cs\n\t"
                                           "popw %%es\n\t"
                                           "int $0x1a\n\t" )
                               : "=a" ( discard_a ), "=b" ( discard_b ),
                                 "=d" ( discard_d )
                               : "0" ( 0x564e ),
                                 "1" ( __from_text16 ( &pxenv ) ) );
}

References __asm__(), __from_text16, __volatile__(), devices_get(), hook_bios_interrupt(), int_1a_hooked, netdev, pxe_int_1a(), pxe_int_1a_vector, pxe_set_netdev(), pxenv, and REAL_CODE.

Referenced by pxe_exec(), pxe_notify(), pxenv_start_undi(), and startpxe_payload().

pxe_deactivate()

int pxe_deactivate

(

void

)

Deactivate PXE stack.

Return values

rc	Return status code

Definition at line 300 of file pxe_call.c.

                            {
        int rc;

        /* Clear PXE network device */
        pxe_set_netdev ( NULL );

        /* Ensure INT 1A is unhooked, if possible */
        if ( int_1a_hooked ) {
                if ( ( rc = unhook_bios_interrupt ( 0x1a,
                                                    ( intptr_t ) pxe_int_1a,
                                                    &pxe_int_1a_vector ))!= 0){
                        DBGC ( &pxe_netdev, "PXE could not unhook INT 1A: %s\n",
                               strerror ( rc ) );
                        return rc;
                }
                devices_put();
                int_1a_hooked = 0;
        }

        return 0;
}

References DBGC, devices_put(), int_1a_hooked, NULL, pxe_int_1a(), pxe_int_1a_vector, pxe_netdev, pxe_set_netdev(), rc, strerror(), and unhook_bios_interrupt().

Referenced by pxe_exec(), pxe_notify(), pxenv_stop_undi(), and stoppxe_exec().

pxe_start_nbp()

int pxe_start_nbp

(

void

)

Start PXE NBP at 0000:7c00.

Return values

rc	Return status code

Definition at line 330 of file pxe_call.c.

                           {
        int jmp;
        int discard_b, discard_c, discard_d, discard_D;
        uint16_t status;

        DBGC ( &pxe_netdev, "PXE NBP starting with netdev %s, code %04x:%04zx, "
               "data %04x:%04zx\n", ( pxe_netdev ? pxe_netdev->name : "<none>"),
               rm_cs, _text16_memsz, rm_ds, _data16_memsz );

        /* Allow restarting NBP via PXENV_RESTART_TFTP */
        jmp = rmsetjmp ( pxe_restart_nbp );
        if ( jmp )
                DBGC ( &pxe_netdev, "PXE NBP restarting (%x)\n", jmp );

        /* Far call to PXE NBP */
        __asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t" /* gcc bug */
                                           "movw %%cx, %%es\n\t"
                                           "pushw %%es\n\t"
                                           "pushw %%di\n\t"
                                           "sti\n\t"
                                           "lcall $0, $0x7c00\n\t"
                                           "popl %%ebp\n\t" /* discard */
                                           "popl %%ebp\n\t" /* gcc bug */ )
                               : "=a" ( status ), "=b" ( discard_b ),
                                 "=c" ( discard_c ), "=d" ( discard_d ),
                                 "=D" ( discard_D )
                               : "a" ( 0 ), "b" ( __from_text16 ( &pxenv ) ),
                                 "c" ( rm_cs ),
                                 "d" ( virt_to_phys ( &pxenv ) ),
                                 "D" ( __from_text16 ( &ppxe ) )
                               : "esi", "memory" );
        if ( status )
                return -EPXENBP ( status );

        return 0;
}

References __asm__(), __from_text16, __volatile__(), _data16_memsz, _text16_memsz, DBGC, discard_c, discard_D, EPXENBP, jmp, net_device::name, ppxe, pxe_netdev, pxe_restart_nbp, pxenv, REAL_CODE, rm_cs, rm_ds, rmsetjmp, and status.

Referenced by pxe_exec().

pxe_notify()

static int pxe_notify ( struct net_device *  netdev, void *priv  __unused  )

static

Notify BIOS of existence of network device.

Parameters

netdev	Network device
priv	Private data

Return values

rc	Return status code

Definition at line 374 of file pxe_call.c.

                                                                         {

        /* Do nothing if we already have a network device */
        if ( pxe_netdev )
                return 0;

        /* Activate (and deactivate) PXE stack to notify BIOS */
        pxe_activate ( netdev );
        pxe_deactivate();

        return 0;
}

References netdev, pxe_activate(), pxe_deactivate(), and pxe_netdev.

REQUIRING_SYMBOL()

REQUIRING_SYMBOL

(

pxe_api_call

)

REQUIRE_OBJECT() [1/5]

REQUIRE_OBJECT

(

pxe_preboot

)

REQUIRE_OBJECT() [2/5]

REQUIRE_OBJECT

(

pxe_undi

)

REQUIRE_OBJECT() [3/5]

REQUIRE_OBJECT

(

pxe_udp

)

REQUIRE_OBJECT() [4/5]

REQUIRE_OBJECT

(

pxe_tftp

)

REQUIRE_OBJECT() [5/5]

REQUIRE_OBJECT

(

pxe_file

)

Variable Documentation

int_1a_hooked

int int_1a_hooked = 0

static

INT 1A hooked flag.

Definition at line 55 of file pxe_call.c.

Referenced by pxe_activate(), and pxe_deactivate().

__profiler

struct profiler pxe_api_misc_profiler __profiler

static

Initial value:

=
        { .name = "pxeapi.tx" }

PXENV_UNDI_TRANSMIT API call profiler.

Miscellaneous PXE API call profiler.

PXE unknown API call profiler.

PXENV_UNDI_ISR API call profiler.

This profiler can be used to measure the overhead of a dummy PXE API call.

Definition at line 66 of file pxe_call.c.

__pxe_api_call

struct pxe_api_call pxenv_unknown_api __pxe_api_call

Initial value:

=
        PXE_API_CALL ( PXENV_UNKNOWN, pxenv_unknown, struct s_PXENV_UNKNOWN )

Unknown PXE API call list.

Definition at line 98 of file pxe_call.c.

pxe_restart_nbp

rmjmp_buf pxe_restart_nbp

Jump buffer for PXENV_RESTART_TFTP.

PXENV_RESTART_TFTP jump buffer.

Definition at line 323 of file pxe_call.c.

Referenced by pxe_start_nbp(), and pxenv_restart_tftp().

__net_driver

struct net_driver pxe_driver __net_driver

Initial value:

= {
        .name = "PXE",
        .probe = pxe_notify,
}

PXE BIOS notification driver.

Definition at line 388 of file pxe_call.c.