diff options
Diffstat (limited to 'cpukit/score/cpu/i386/cpu_asm.S')
| -rw-r--r-- | cpukit/score/cpu/i386/cpu_asm.S | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/cpukit/score/cpu/i386/cpu_asm.S b/cpukit/score/cpu/i386/cpu_asm.S new file mode 100644 index 0000000000..418d2bf787 --- /dev/null +++ b/cpukit/score/cpu/i386/cpu_asm.S @@ -0,0 +1,320 @@ +/* cpu_asm.s + * + * This file contains all assembly code for the Intel i386 implementation + * of RTEMS. + * + * COPYRIGHT (c) 1989-1999. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <rtems/asm.h> +#include <rtems/score/cpu.h> + +#ifndef CPU_STACK_ALIGNMENT +#error "Missing header? CPU_STACK_ALIGNMENT not defined" +#endif + +/* + * Format of i386 Register structure + */ + +.set REG_EFLAGS, 0 +.set REG_ESP, REG_EFLAGS + 4 +.set REG_EBP, REG_ESP + 4 +.set REG_EBX, REG_EBP + 4 +.set REG_ESI, REG_EBX + 4 +.set REG_EDI, REG_ESI + 4 +.set SIZE_REGS, REG_EDI + 4 + + BEGIN_CODE + +/* + * void _CPU_Context_switch( run_context, heir_context ) + * + * This routine performs a normal non-FP context. + */ + + .p2align 1 + PUBLIC (_CPU_Context_switch) + +.set RUNCONTEXT_ARG, 4 /* save context argument */ +.set HEIRCONTEXT_ARG, 8 /* restore context argument */ + +SYM (_CPU_Context_switch): + movl RUNCONTEXT_ARG(esp),eax /* eax = running threads context */ + pushf /* push eflags */ + popl REG_EFLAGS(eax) /* save eflags */ + movl esp,REG_ESP(eax) /* save stack pointer */ + movl ebp,REG_EBP(eax) /* save base pointer */ + movl ebx,REG_EBX(eax) /* save ebx */ + movl esi,REG_ESI(eax) /* save source register */ + movl edi,REG_EDI(eax) /* save destination register */ + + movl HEIRCONTEXT_ARG(esp),eax /* eax = heir threads context */ + +restore: + pushl REG_EFLAGS(eax) /* push eflags */ + popf /* restore eflags */ + movl REG_ESP(eax),esp /* restore stack pointer */ + movl REG_EBP(eax),ebp /* restore base pointer */ + movl REG_EBX(eax),ebx /* restore ebx */ + movl REG_ESI(eax),esi /* restore source register */ + movl REG_EDI(eax),edi /* restore destination register */ + ret + +/* + * NOTE: May be unnecessary to reload some registers. + */ + +/* + * void _CPU_Context_restore( new_context ) + * + * This routine performs a normal non-FP context. + */ + + PUBLIC (_CPU_Context_restore) + +.set NEWCONTEXT_ARG, 4 /* context to restore argument */ + +SYM (_CPU_Context_restore): + movl NEWCONTEXT_ARG(esp),eax /* eax = running threads context */ + jmp restore + +/*PAGE + * void _CPU_Context_save_fp_context( &fp_context_ptr ) + * void _CPU_Context_restore_fp_context( &fp_context_ptr ) + * + * This section is used to context switch an i80287, i80387, + * the built-in coprocessor or the i80486 or compatible. + */ + +.set FPCONTEXT_ARG, 4 /* FP context argument */ + +#ifndef __SSE__ + .p2align 1 + PUBLIC (_CPU_Context_save_fp) +SYM (_CPU_Context_save_fp): + movl FPCONTEXT_ARG(esp),eax /* eax = &ptr to FP context area */ + movl (eax),eax /* eax = FP context area */ + fsave (eax) /* save FP context */ + ret + + .p2align 1 + PUBLIC (_CPU_Context_restore_fp) +SYM (_CPU_Context_restore_fp): + movl FPCONTEXT_ARG(esp),eax /* eax = &ptr to FP context area */ + movl (eax),eax /* eax = FP context area */ + frstor (eax) /* restore FP context */ + ret +#endif + +#ifdef __SSE__ +#define SSE_OFF 16 +#endif + + PUBLIC (_Exception_Handler) +SYM (_Exception_Handler): + pusha /* Push general purpose registers */ + pushl $0 /* Null pointer to SSE area */ + movl esp, ebp /* Save original SP */ +#ifndef __SSE__ + subl $4, esp /* Reserve space for argument */ + /* Align stack (courtesy for C/gcc) */ + andl $ - CPU_STACK_ALIGNMENT, esp +#else + subl $512, esp /* Space for SSE area */ + /* Align stack (courtesy for C/gcc) */ + andl $ - CPU_STACK_ALIGNMENT, esp +/* Doing fwait here will re-throw an already pending FP exception! + fwait + */ + fxsave 0(esp) + fninit /* Clean-slate FPU */ + movl $0x1f80, 0(ebp) + ldmxcsr 0(ebp) /* Clean-slate MXCSR */ + movl esp, 0(ebp) /* Store pointer to SSE area */ + subl $SSE_OFF, esp /* Aligned space for argument */ +#endif + movl ebp, (esp) /* Store argument */ + movl _currentExcHandler, eax /* Call function stored in _currentExcHandler */ + call * eax +#ifdef __SSE__ + fwait + fxrstor 16(esp) +#endif + movl ebp, esp /* Restore original SP */ + addl $4, esp /* Skill pointer to SSE area */ + popa /* Restore general purpose registers */ + addl $8, esp /* Skill vector number and faultCode */ + iret + +#define DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY(_vector) \ + .p2align 4 ; \ + PUBLIC (rtems_exception_prologue_ ## _vector ) ; \ +SYM (rtems_exception_prologue_ ## _vector ): \ + pushl $ _vector ; \ + jmp SYM (_Exception_Handler) ; + +#define DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY(_vector) \ + .p2align 4 ; \ + PUBLIC (rtems_exception_prologue_ ## _vector ) ; \ +SYM (rtems_exception_prologue_ ## _vector ): \ + pushl $ 0 ; \ + pushl $ _vector ; \ + jmp SYM (_Exception_Handler) ; + +/* + * Divide Error + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (0) +/* + * Debug Exception + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (1) +/* + * NMI + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (2) +/* + * Breakpoint + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (3) +/* + * Overflow + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (4) +/* + * Bound Range Exceeded + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (5) +/* + * Invalid Opcode + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (6) +/* + * No Math Coproc + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (7) +/* + * Double Fault + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (8) +/* + * Coprocessor segment overrun + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (9) +/* + * Invalid TSS + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (10) +/* + * Segment Not Present + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (11) +/* + * Stack segment Fault + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (12) +/* + * General Protection Fault + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (13) +/* + * Page Fault + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (14) +/* + * Floating point error (NB 15 is reserved it is therefor skipped) + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (16) +/* + * Aligment Check + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (17) +/* + * Machine Check + */ +DISTINCT_EXCEPTION_WITH_FAULTCODE_ENTRY (18) + +#ifdef __SSE__ +/* + * SIMD FP Exception + */ +DISTINCT_EXCEPTION_WITHOUT_FAULTCODE_ENTRY (19) +#endif + + +/* + * void *i386_Logical_to_physical( + * uint16_t segment, + * void *address + * ); + * + * Returns thirty-two bit physical address for segment:address. + */ + +.set SEGMENT_ARG, 4 +.set ADDRESS_ARG, 8 + + PUBLIC (i386_Logical_to_physical) + +SYM (i386_Logical_to_physical): + + xorl eax,eax /* clear eax */ + movzwl SEGMENT_ARG(esp),ecx /* ecx = segment value */ + movl $ SYM (_Global_descriptor_table),edx + /* edx = address of our GDT */ + addl ecx,edx /* edx = address of desired entry */ + movb 7(edx),ah /* ah = base 31:24 */ + movb 4(edx),al /* al = base 23:16 */ + shll $16,eax /* move ax into correct bits */ + movw 2(edx),ax /* ax = base 0:15 */ + movl ADDRESS_ARG(esp),ecx /* ecx = address to convert */ + addl eax,ecx /* ecx = physical address equivalent */ + movl ecx,eax /* eax = ecx */ + ret + +/* + * void *i386_Physical_to_logical( + * uint16_t segment, + * void *address + * ); + * + * Returns thirty-two bit physical address for segment:address. + */ + +/* + *.set SEGMENT_ARG, 4 + *.set ADDRESS_ARG, 8 -- use sets from above + */ + + PUBLIC (i386_Physical_to_logical) + +SYM (i386_Physical_to_logical): + xorl eax,eax /* clear eax */ + movzwl SEGMENT_ARG(esp),ecx /* ecx = segment value */ + movl $ SYM (_Global_descriptor_table),edx + /* edx = address of our GDT */ + addl ecx,edx /* edx = address of desired entry */ + movb 7(edx),ah /* ah = base 31:24 */ + movb 4(edx),al /* al = base 23:16 */ + shll $16,eax /* move ax into correct bits */ + movw 2(edx),ax /* ax = base 0:15 */ + movl ADDRESS_ARG(esp),ecx /* ecx = address to convert */ + subl eax,ecx /* ecx = logical address equivalent */ + movl ecx,eax /* eax = ecx */ + ret + +END_CODE + +END |