From ac7d5ef06a6d6e8d84abbd1f0b82162725f98326 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Thu, 11 May 1995 17:39:37 +0000 Subject: Initial revision --- cpukit/score/cpu/i386/cpu.c | 121 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 cpukit/score/cpu/i386/cpu.c (limited to 'cpukit/score/cpu/i386/cpu.c') diff --git a/cpukit/score/cpu/i386/cpu.c b/cpukit/score/cpu/i386/cpu.c new file mode 100644 index 0000000000..05a836f7e3 --- /dev/null +++ b/cpukit/score/cpu/i386/cpu.c @@ -0,0 +1,121 @@ +/* + * Intel i386 Dependent Source + * + * + * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. + * On-Line Applications Research Corporation (OAR). + * All rights assigned to U.S. Government, 1994. + * + * This material may be reproduced by or for the U.S. Government pursuant + * to the copyright license under the clause at DFARS 252.227-7013. This + * notice must appear in all copies of this file and its derivatives. + * + * $Id$ + */ + +#include +#include +#include +#include + +/* _CPU_Initialize + * + * This routine performs processor dependent initialization. + * + * INPUT PARAMETERS: + * cpu_table - CPU table to initialize + * thread_dispatch - address of disptaching routine + */ + + +void _CPU_Initialize( + rtems_cpu_table *cpu_table, + void (*thread_dispatch) /* ignored on this CPU */ +) +{ + register unsigned16 fp_status asm ("ax"); + register unsigned8 *fp_context; + + if ( cpu_table == NULL ) + rtems_fatal_error_occurred( RTEMS_NOT_CONFIGURED ); + + _CPU_Table = *cpu_table; + + /* + * The following code saves a NULL i387 context which is given + * to each task at start and restart time. The following code + * is based upon that provided in the i386 Programmer's + * Manual and should work on any coprocessor greater than + * the i80287. + * + * NOTE: The NO RTEMS_WAIT form of the coprocessor instructions + * MUST be used in case there is not a coprocessor + * to wait for. + */ + + fp_status = 0xa5a5; + asm volatile( "fninit" ); + asm volatile( "fnstsw %0" : "=a" (fp_status) : "0" (fp_status) ); + + if ( fp_status == 0 ) { + + fp_context = _CPU_Null_fp_context; + + asm volatile( "fsave (%0)" : "=r" (fp_context) + : "0" (fp_context) + ); + } +} + +/* _CPU_ISR_install_vector + * + * This kernel routine installs the RTEMS handler for the + * specified vector. + * + * Input parameters: + * vector - interrupt vector number + * old_handler - former ISR for this vector number + * new_handler - replacement ISR for this vector number + * + * Output parameters: NONE + * + */ + +void _ISR_Handler_0(), _ISR_Handler_1(); + +#define PER_ISR_ENTRY \ + (((unsigned32) _ISR_Handler_1 - (unsigned32) _ISR_Handler_0)) + +#define _Interrupt_Handler_entry( _vector ) \ + (((unsigned32)_ISR_Handler_0) + ((_vector) * PER_ISR_ENTRY)) + +void _CPU_ISR_install_vector( + unsigned32 vector, + proc_ptr new_handler, + proc_ptr *old_handler +) +{ + i386_IDT_slot idt; + unsigned32 unique_handler; + + /* calculate the unique entry point for this vector */ + unique_handler = _Interrupt_Handler_entry( vector ); + + /* build the IDT entry */ + idt.offset_0_15 = ((unsigned32) unique_handler) & 0xffff; + idt.segment_selector = i386_get_cs(); + idt.reserved = 0x00; + idt.p_dpl = 0x8e; /* present, ISR */ + idt.offset_16_31 = ((unsigned32) unique_handler) >> 16; + + /* install the IDT entry */ + i386_Install_idt( + (unsigned32) &idt, + _CPU_Table.interrupt_table_segment, + (unsigned32) _CPU_Table.interrupt_table_offset + (8 * vector) + ); + + /* "portable" part */ + *old_handler = _ISR_Vector_table[ vector ]; + _ISR_Vector_table[ vector ] = new_handler; +} -- cgit v1.2.3