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Diffstat (limited to 'c/src/lib/libbsp/i386/pc386/startup/ldsegs.S')
| -rw-r--r-- | c/src/lib/libbsp/i386/pc386/startup/ldsegs.S | 238 |
1 files changed, 0 insertions, 238 deletions
diff --git a/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S b/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S deleted file mode 100644 index b56bf836f0..0000000000 --- a/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S +++ /dev/null @@ -1,238 +0,0 @@ -/*-------------------------------------------------------------------------+ -| ldsegs.s v1.1 - PC386 BSP - 1997/08/07 -+--------------------------------------------------------------------------+ -| This file assists the board independent startup code by loading the proper -| segment register values. The values loaded are board dependent. In addition -| it contains code to enable the A20 line and to reprogram the PIC to relocate -| the IRQ interrupt vectors to 0x20 -> 0x2f. -| NOTE: No stack has been established when this routine is invoked. -| It returns by jumping back to bspentry. -+--------------------------------------------------------------------------+ -| (C) Copyright 1997 - -| - NavIST Group - Real-Time Distributed Systems and Industrial Automation -| -| http://pandora.ist.utl.pt -| -| Instituto Superior Tecnico * Lisboa * PORTUGAL -+--------------------------------------------------------------------------+ -| Disclaimer: -| -| This file is provided "AS IS" without warranty of any kind, either -| expressed or implied. -+--------------------------------------------------------------------------+ -| This code is base on: -| ldsegs.s,v 1.4 1996/04/20 16:48:30 joel Exp - go32 BSP -| With the following copyright notice: -| ************************************************************************** -| * 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.org/license/LICENSE. -| ************************************************************************** -+--------------------------------------------------------------------------*/ - -#include <rtems/asm.h> -#include <bsp/tblsizes.h> /* contains sizes of GDT and IDT */ -#include <bspopts.h> - -/*----------------------------------------------------------------------------+ -| CODE section -+----------------------------------------------------------------------------*/ -EXTERN (rtems_i8259_masks) - -BEGIN_CODE - - EXTERN (_establish_stack) - EXTERN (Timer_exit) - EXTERN (clockOff) - -/*----------------------------------------------------------------------------+ -| pc386_delay -+------------------------------------------------------------------------------ -| Delay is needed after doing I/O. -| -| The outb version is OK on most machines BUT the loop version ... -| -| will delay for 1us on 1Gz machine, it will take a little bit -| longer on slower machines, however, it does not matter because we -| are going to call this function only a few times - -+----------------------------------------------------------------------------*/ -#define DELAY_USE_OUTB - - .p2align 4 - .globl _pc386_delay - .globl pc386_delay -pc386_delay: -_pc386_delay: -#ifdef DELAY_USE_OUTB - outb al, $0x80 # about 1uS delay on most machines -#else - movl $0x200, eax -pc386_delay1: - dec eax - jnz pc386_delay1 -#endif - ret - -/*-------------------------------------------------------------------------+ -| Function: _load_segments -| Description: Current environment is standard PC booted by grub. -| So, there is no value in saving current GDT and IDT -| settings we have to set it up ourseves. (Naturally -| it will be not so in case we are booted by some -| boot monitor, however, then it will be different -| BSP). After that we have to load board segment registers -| with apropriate values + reprogram PIC. -| Global Variables: None. -| Arguments: None. -| Returns: Nothing. -+--------------------------------------------------------------------------*/ - .p2align 4 - - PUBLIC (_load_segments) -SYM (_load_segments): - - lgdt SYM(gdtdesc) - lidt SYM(IDT_Descriptor) - - /* Load CS, flush prefetched queue */ - ljmp $0x8, $next_step - -next_step: - /* Load segment registers */ - movw $0x10, ax - movw ax, ss - movw ax, ds - movw ax, es - movw ax, fs - movw ax, gs - -/*---------------------------------------------------------------------+ -| Now we have to reprogram the interrupts :-(. We put them right after -| the intel-reserved hardware interrupts, at int 0x20-0x2F. There they -| won't mess up anything. Sadly IBM really messed this up with the -| original PC, and they haven't been able to rectify it afterwards. Thus -| the bios puts interrupts at 0x08-0x0f, which is used for the internal -| hardware interrupts as well. We just have to reprogram the 8259's, and -| it isn't fun. -+---------------------------------------------------------------------*/ - - movb $0x11, al /* initialization sequence */ - outb al, $0x20 /* send it to 8259A-1 */ - call SYM(pc386_delay) - outb al, $0xA0 /* and to 8259A-2 */ - call SYM(pc386_delay) - - movb $0x20, al /* start of hardware int's (0x20) */ - outb al, $0x21 - call SYM(pc386_delay) - movb $0x28, al /* start of hardware int's 2 (0x28) */ - outb al, $0xA1 - call SYM(pc386_delay) - - movb $0x04, al /* 8259-1 is master */ - outb al, $0x21 - call SYM(pc386_delay) - movb $0x02, al /* 8259-2 is slave */ - outb al, $0xA1 - call SYM(pc386_delay) - - movb $0x01, al /* 8086 mode for both */ - outb al, $0x21 - call SYM(pc386_delay) - outb al, $0xA1 - call SYM(pc386_delay) - - /* - * The IMR values must correspond to the initial value of i8259s_cache. - */ - movb $0xFF, al /* mask off all interrupts for now */ - outb al, $0xA1 - call SYM(pc386_delay) - movb $0xFB, al /* mask all irq's but irq2 which */ - outb al, $0x21 /* is cascaded */ - call SYM(pc386_delay) - jmp SYM (_establish_stack) # return to the bsp entry code - -/*-------------------------------------------------------------------------+ -| Function: _default_int_handler -| Description: default interrupt handler -| Global Variables: None. -| Arguments: None. -| Returns: Nothing. -+--------------------------------------------------------------------------*/ - .p2align 4 - -/*---------------------------------------------------------------------------+ -| GDT itself -+--------------------------------------------------------------------------*/ -#if GDT_SIZE < NUM_SYSTEM_GDT_DESCRIPTORS -#error "GDT_SIZE must be at least NUM_SYSTEM_GDT_DESCRIPTORS" -#endif - -BEGIN_DATA - .p2align 4 - - PUBLIC (_Global_descriptor_table) -SYM (_Global_descriptor_table): - - /* NULL segment */ - .word 0, 0 - .byte 0, 0, 0, 0 - - /* code segment */ - .word 0xffff, 0 - .byte 0, 0x9e, 0xcf, 0 - - /* data segment */ - .word 0xffff, 0 - .byte 0, 0x92, 0xcf, 0 - - /* gs segment */ - .word 0xffff, 0 - .byte 0, 0x92, 0xcf, 0 - - /* allocated space for user segments */ - .rept (GDT_SIZE - NUM_SYSTEM_GDT_DESCRIPTORS) - .word 0,0,0,0 - .endr - -/*---------------------------------------------------------------------------+ -| Descriptor of GDT -+--------------------------------------------------------------------------*/ - PUBLIC(gdtdesc) -SYM(gdtdesc): - .word (GDT_SIZE*8 - 1) - .long SYM (_Global_descriptor_table) - -/*---------------------------------------------------------------------------+ -| IDT itself -+---------------------------------------------------------------------------*/ - .p2align 4 - - PUBLIC(Interrupt_descriptor_table) -SYM(Interrupt_descriptor_table): - .rept IDT_SIZE - .word 0,0,0,0 - .endr - -/*---------------------------------------------------------------------------+ -| Descriptor of IDT -+--------------------------------------------------------------------------*/ - - .p2align 4 - PUBLIC(IDT_Descriptor) -SYM(IDT_Descriptor): - .word (IDT_SIZE*8 - 1) - .long SYM (Interrupt_descriptor_table) - -END_DATA - - .section .m_hdr - .long 0x1BADB002 - .long 0 - .long 0xE4524FFE -END |