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- /* 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 */
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