/* PXE callback mechanisms. This file contains only the portions
* specific to i386: i.e. the low-level mechanisms for calling in from
* an NBP to the PXE stack and for starting an NBP from the PXE stack.
*/
#warning "pxe_callbacks.c is temporarily broken"
void xstartpxe ( void ) {
}
void install_pxe_stack ( void ) {
}
void remove_pxe_stack ( void ) {
}
void hook_pxe_stack ( void ) {
}
void unhook_pxe_stack ( void ) {
}
void pxe_in_call ( void ) {
}
void use_undi_ds_for_rm_stack ( void ) {
}
#if 0
#ifdef PXE_EXPORT
#include "etherboot.h"
#include "callbacks.h"
#include "realmode.h"
#include "pxe.h"
#include "pxe_callbacks.h"
#include "pxe_export.h"
#include "hidemem.h"
#include <stdarg.h>
#define INSTALLED(x) ( (typeof(&x)) ( (void*)(&x) \
- &pxe_callback_interface \
+ (void*)&pxe_stack->arch_data ) )
#define pxe_intercept_int1a INSTALLED(_pxe_intercept_int1a)
#define pxe_intercepted_int1a INSTALLED(_pxe_intercepted_int1a)
#define pxe_pxenv_location INSTALLED(_pxe_pxenv_location)
#define INT1A_VECTOR ( (segoff_t*) ( phys_to_virt( 4 * 0x1a ) ) )
/* The overall size of the PXE stack is ( sizeof(pxe_stack_t) +
* pxe_callback_interface_size + rm_callback_interface_size ).
* Unfortunately, this isn't a compile-time constant, since
* {pxe,rm}_callback_interface_size depend on the length of the
* assembly code in these interfaces.
*
* We used to have a function pxe_stack_size() which returned this
* value. However, it actually needs to be a link-time constant, so
* that it can appear in the UNDIROMID structure in romprefix.S. We
* therefore export the three component sizes as absolute linker
* symbols, get the linker to add them together and generate a new
* absolute symbol _pxe_stack_size. We then import this value into a
* C variable pxe_stack_size, for access from C code.
*/
/* gcc won't let us use extended asm outside a function (compiler
* bug), ao we have to put these asm statements inside a dummy
* function.
*/
static void work_around_gcc_bug ( void ) __attribute__ ((used));
static void work_around_gcc_bug ( void ) {
/* Export sizeof(pxe_stack_t) as absolute linker symbol */
__asm__ ( ".globl _pxe_stack_t_size" );
__asm__ ( ".equ _pxe_stack_t_size, %c0"
: : "i" (sizeof(pxe_stack_t)) );
}
/* Import _pxe_stack_size absolute linker symbol into C variable */
extern int pxe_stack_size;
__asm__ ( "pxe_stack_size: .long _pxe_stack_size" );
/* Utility routine: byte checksum
*/
uint8_t byte_checksum ( void *address, size_t size ) {
unsigned int i, sum = 0;
for ( i = 0; i < size; i++ ) {
sum += ((uint8_t*)address)[i];
}
return (uint8_t)sum;
}
/* install_pxe_stack(): install PXE stack.
*
* Use base = NULL for auto-allocation of base memory
*
* IMPORTANT: no further allocation of base memory should take place
* before the PXE stack is removed. This is to work around a small
* but important deficiency in the PXE specification.
*/
pxe_stack_t * install_pxe_stack ( void *base ) {
pxe_t *pxe;
pxenv_t *pxenv;
void *pxe_callback_code;
void (*pxe_in_call_far)(void);
void (*pxenv_in_call_far)(void);
void *rm_callback_code;
void *e820mangler_code;
void *end;
/* If already installed, just return */
if ( pxe_stack != NULL ) return pxe_stack;
/* Allocate base memory if requested to do so
*/
if ( base == NULL ) {
base = allot_base_memory ( pxe_stack_size );
if ( base == NULL ) return NULL;
}
/* Round address up to 16-byte physical alignment */
pxe_stack = (pxe_stack_t *)
( phys_to_virt ( ( virt_to_phys(base) + 0xf ) & ~0xf ) );
/* Zero out allocated stack */
memset ( pxe_stack, 0, sizeof(*pxe_stack) );
/* Calculate addresses for portions of the stack */
pxe = &(pxe_stack->pxe);
pxenv = &(pxe_stack->pxenv);
pxe_callback_code = &(pxe_stack->arch_data);
pxe_in_call_far = _pxe_in_call_far +
( pxe_callback_code - &pxe_callback_interface );
pxenv_in_call_far = _pxenv_in_call_far +
( pxe_callback_code - &pxe_callback_interface );
rm_callback_code = pxe_callback_code + pxe_callback_interface_size;
e820mangler_code = (void*)(((int)rm_callback_code +
rm_callback_interface_size + 0xf ) & ~0xf);
end = e820mangler_code + e820mangler_size;
/* Initialise !PXE data structures */
memcpy ( pxe->Signature, "!PXE", 4 );
pxe->StructLength = sizeof(*pxe);
pxe->StructRev = 0;
pxe->reserved_1 = 0;
/* We don't yet have an UNDI ROM ID structure */
pxe->UNDIROMID.segment = 0;
pxe->UNDIROMID.offset = 0;
/* or a BC ROM ID structure */
pxe->BaseROMID.segment = 0;
pxe->BaseROMID.offset = 0;
pxe->EntryPointSP.segment = SEGMENT(pxe_stack);
pxe->EntryPointSP.offset = (void*)pxe_in_call_far - (void*)pxe_stack;
/* No %esp-compatible entry point yet */
pxe->EntryPointESP.segment = 0;
pxe->EntryPointESP.offset = 0;
pxe->StatusCallout.segment = -1;
pxe->StatusCallout.offset = -1;
pxe->reserved_2 = 0;
pxe->SegDescCn = 7;
pxe->FirstSelector = 0;
/* PXE specification doesn't say anything about when the stack
* space should get freed. We work around this by claiming it
* as our data segment as well.
*/
pxe->Stack.Seg_Addr = pxe->UNDIData.Seg_Addr = real_mode_stack >> 4;
pxe->Stack.Phy_Addr = pxe->UNDIData.Phy_Addr = real_mode_stack;
pxe->Stack.Seg_Size = pxe->UNDIData.Seg_Size = real_mode_stack_size;
/* Code segment has to be the one containing the data structures... */
pxe->UNDICode.Seg_Addr = SEGMENT(pxe_stack);
pxe->UNDICode.Phy_Addr = virt_to_phys(pxe_stack);
pxe->UNDICode.Seg_Size = end - (void*)pxe_stack;
/* No base code loaded */
pxe->BC_Data.Seg_Addr = 0;
pxe->BC_Data.Phy_Addr = 0;
pxe->BC_Data.Seg_Size = 0;
pxe->BC_Code.Seg_Addr = 0;
pxe->BC_Code.Phy_Addr = 0;
pxe->BC_Code.Seg_Size = 0;
pxe->BC_CodeWrite.Seg_Addr = 0;
pxe->BC_CodeWrite.Phy_Addr = 0;
pxe->BC_CodeWrite.Seg_Size = 0;
pxe->StructCksum -= byte_checksum ( pxe, sizeof(*pxe) );
/* Initialise PXENV+ data structures */
memcpy ( pxenv->Signature, "PXENV+", 6 );
pxenv->Version = 0x201;
pxenv->Length = sizeof(*pxenv);
pxenv->RMEntry.segment = SEGMENT(pxe_stack);
pxenv->RMEntry.offset = (void*)pxenv_in_call_far - (void*)pxe_stack;
pxenv->PMOffset = 0; /* "Do not use" says the PXE spec */
pxenv->PMSelector = 0; /* "Do not use" says the PXE spec */
pxenv->StackSeg = pxenv->UNDIDataSeg = real_mode_stack >> 4;
pxenv->StackSize = pxenv->UNDIDataSize = real_mode_stack_size;
pxenv->BC_CodeSeg = 0;
pxenv->BC_CodeSize = 0;
pxenv->BC_DataSeg = 0;
pxenv->BC_DataSize = 0;
/* UNDIData{Seg,Size} set above */
pxenv->UNDICodeSeg = SEGMENT(pxe_stack);
pxenv->UNDICodeSize = end - (void*)pxe_stack;
pxenv->PXEPtr.segment = SEGMENT(pxe);
pxenv->PXEPtr.offset = OFFSET(pxe);
pxenv->Checksum -= byte_checksum ( pxenv, sizeof(*pxenv) );
/* Mark stack as inactive */
pxe_stack->state = CAN_UNLOAD;
/* Install PXE and RM callback code and E820 mangler */
memcpy ( pxe_callback_code, &pxe_callback_interface,
pxe_callback_interface_size );
install_rm_callback_interface ( rm_callback_code, 0 );
install_e820mangler ( e820mangler_code );
return pxe_stack;
}
/* Use the UNDI data segment as our real-mode stack. This is for when
* we have been loaded via the UNDI loader
*/
void use_undi_ds_for_rm_stack ( uint16_t ds ) {
forget_real_mode_stack();
real_mode_stack = virt_to_phys ( VIRTUAL ( ds, 0 ) );
lock_real_mode_stack = 1;
}
/* Activate PXE stack (i.e. hook interrupt vectors). The PXE stack
* *can* be used before it is activated, but it really shoudln't.
*/
int hook_pxe_stack ( void ) {
if ( pxe_stack == NULL ) return 0;
if ( pxe_stack->state >= MIDWAY ) return 1;
/* Hook INT15 handler */
hide_etherboot();
/* Hook INT1A handler */
*pxe_intercepted_int1a = *INT1A_VECTOR;
pxe_pxenv_location->segment = SEGMENT(pxe_stack);
pxe_pxenv_location->offset = (void*)&pxe_stack->pxenv
- (void*)pxe_stack;
INT1A_VECTOR->segment = SEGMENT(&pxe_stack->arch_data);
INT1A_VECTOR->offset = (void*)pxe_intercept_int1a
- (void*)&pxe_stack->arch_data;
/* Mark stack as active */
pxe_stack->state = MIDWAY;
return 1;
}
/* Deactivate the PXE stack (i.e. unhook interrupt vectors).
*/
int unhook_pxe_stack ( void ) {
if ( pxe_stack == NULL ) return 0;
if ( pxe_stack->state <= CAN_UNLOAD ) return 1;
/* Restore original INT15 and INT1A handlers */
*INT1A_VECTOR = *pxe_intercepted_int1a;
if ( !unhide_etherboot() ) {
/* Cannot unhook INT15. We're up the creek without
* even a suitable log out of which to fashion a
* paddle. There are some very badly behaved NBPs
* that will ignore plaintive pleas such as
* PXENV_KEEP_UNDI and just zero out our code anyway.
* This means they end up vapourising an active INT15
* handler, which is generally not a good thing to do.
*/
return 0;
}
/* Mark stack as inactive */
pxe_stack->state = CAN_UNLOAD;
return 1;
}
/* remove_pxe_stack(): remove PXE stack installed by install_pxe_stack()
*/
void remove_pxe_stack ( void ) {
/* Ensure stack is deactivated, then free up the memory */
if ( ensure_pxe_state ( CAN_UNLOAD ) ) {
forget_base_memory ( pxe_stack, pxe_stack_size );
pxe_stack = NULL;
} else {
printf ( "Cannot remove PXE stack!\n" );
}
}
/* xstartpxe(): start up a PXE image
*/
int xstartpxe ( void ) {
int nbp_exit;
struct {
reg16_t bx;
reg16_t es;
segoff_t pxe;
} PACKED in_stack;
/* Set up registers and stack parameters to pass to PXE NBP */
in_stack.es.word = SEGMENT(&(pxe_stack->pxenv));
in_stack.bx.word = OFFSET(&(pxe_stack->pxenv));
in_stack.pxe.segment = SEGMENT(&(pxe_stack->pxe));
in_stack.pxe.offset = OFFSET(&(pxe_stack->pxe));
/* Real-mode trampoline fragment used to jump to PXE NBP
*/
RM_FRAGMENT(jump_to_pxe_nbp,
"popw %bx\n\t"
"popw %es\n\t"
"lcall $" RM_STR(PXE_LOAD_SEGMENT) ", $" RM_STR(PXE_LOAD_OFFSET) "\n\t"
);
/* Call to PXE image */
gateA20_unset();
nbp_exit = real_call ( jump_to_pxe_nbp, &in_stack, NULL );
gateA20_set();
return nbp_exit;
}
int pxe_in_call ( in_call_data_t *in_call_data, va_list params ) {
/* i386 calling conventions; the only two defined by Intel's
* PXE spec.
*
* Assembly code must pass a long containing the PXE version
* code (i.e. 0x201 for !PXE, 0x200 for PXENV+) as the first
* parameter after the in_call opcode. This is used to decide
* whether to take parameters from the stack (!PXE) or from
* registers (PXENV+).
*/
uint32_t api_version = va_arg ( params, typeof(api_version) );
uint16_t opcode;
segoff_t segoff;
t_PXENV_ANY *structure;
if ( api_version >= 0x201 ) {
/* !PXE calling convention */
pxe_call_params_t pxe_params
= va_arg ( params, typeof(pxe_params) );
opcode = pxe_params.opcode;
segoff = pxe_params.segoff;
} else {
/* PXENV+ calling convention */
opcode = in_call_data->pm->regs.bx;
segoff.segment = in_call_data->rm->seg_regs.es;
segoff.offset = in_call_data->pm->regs.di;
}
structure = VIRTUAL ( segoff.segment, segoff.offset );
return pxe_api_call ( opcode, structure );
}
#ifdef TEST_EXCLUDE_ALGORITHM
/* This code retained because it's a difficult algorithm to tweak with
* confidence
*/
int ___test_exclude ( int start, int len, int estart, int elen, int fixbase );
void __test_exclude ( int start, int len, int estart, int elen, int fixbase ) {
int newrange = ___test_exclude ( start, len, estart, elen, fixbase );
int newstart = ( newrange >> 16 ) & 0xffff;
int newlen = ( newrange & 0xffff );
printf ( "[%x,%x): excluding [%x,%x) %s gives [%x,%x)\n",
start, start + len,
estart, estart + elen,
( fixbase == 0 ) ? " " : "fb",
newstart, newstart + newlen );
}
void _test_exclude ( int start, int len, int estart, int elen ) {
__test_exclude ( start, len, estart, elen, 0 );
__test_exclude ( start, len, estart, elen, 1 );
}
void test_exclude ( void ) {
_test_exclude ( 0x8000, 0x1000, 0x0400, 0x200 ); /* before */
_test_exclude ( 0x8000, 0x1000, 0x9000, 0x200 ); /* after */
_test_exclude ( 0x8000, 0x1000, 0x7f00, 0x200 ); /* before overlap */
_test_exclude ( 0x8000, 0x1000, 0x8f00, 0x200 ); /* after overlap */
_test_exclude ( 0x8000, 0x1000, 0x8000, 0x200 ); /* align start */
_test_exclude ( 0x8000, 0x1000, 0x8e00, 0x200 ); /* align end */
_test_exclude ( 0x8000, 0x1000, 0x8100, 0x200 ); /* early overlap */
_test_exclude ( 0x8000, 0x1000, 0x8d00, 0x200 ); /* late overlap */
_test_exclude ( 0x8000, 0x1000, 0x7000, 0x3000 ); /* total overlap */
_test_exclude ( 0x8000, 0x1000, 0x8000, 0x1000 ); /* exact overlap */
}
#endif /* TEST_EXCLUDE_ALGORITHM */
#else /* PXE_EXPORT */
/* Define symbols used by the linker scripts, to prevent link errors */
__asm__ ( ".globl _pxe_stack_t_size" );
__asm__ ( ".equ _pxe_stack_t_size, 0" );
#endif /* PXE_EXPORT */
#endif /* 0 */
