diff options
Diffstat (limited to 'c/src/lib/libbsp/i386/force386/start/start.S')
| -rw-r--r-- | c/src/lib/libbsp/i386/force386/start/start.S | 267 |
1 files changed, 0 insertions, 267 deletions
diff --git a/c/src/lib/libbsp/i386/force386/start/start.S b/c/src/lib/libbsp/i386/force386/start/start.S deleted file mode 100644 index c1d0ffd099..0000000000 --- a/c/src/lib/libbsp/i386/force386/start/start.S +++ /dev/null @@ -1,267 +0,0 @@ -/* start.s - * - * This file contains the entry point for the application. - * The name of this entry point is compiler dependent. - * It jumps to the BSP which is responsible for performing - * all initialization. - * - * - * COPYRIGHT (c) 1989-1998. - * On-Line Applications Research Corporation (OAR). - * Copyright assigned to U.S. Government, 1994. - * - * The license and distribution terms for this file may be - * found in the file LICENSE in this distribution or at - * http://www.OARcorp.com/rtems/license.html. - * - * $Id$ - */ - -#include "asm.h" - -/* - * A Descriptor table register has the following format - */ - -.set DTR_LIMIT, 0 # offset of two byte limit -.set DTR_BASE, 2 # offset of four byte base address -.set DTR_SIZE, 6 # size of DTR register - - BEGIN_DATA - EXTERN (Do_Load_IDT) - EXTERN (Do_Load_GDT) - END_DATA - - BEGIN_CODE - - PUBLIC (start) # GNU default entry point - - EXTERN (boot_card) - EXTERN (load_segments) - EXTERN (exit) - -SYM (start): - nop - cli # DISABLE INTERRUPTS!!! -/* - * Load the segment registers - * - * NOTE: Upon return, gs will contain the segment descriptor for - * a segment which maps directly to all of physical memory. - */ - jmp SYM (_load_segments) # load board dependent segments - -/* - * Set up the stack - */ - - PUBLIC (_establish_stack) -SYM (_establish_stack): - - movl $end,eax # eax = end of bss/start of heap - addl $heap_size,eax # eax = end of heap - movl eax,stack_start # Save for brk() routine - addl $stack_size,eax # make room for stack - andl $0xffffffc0,eax # align it on 16 byte boundary - movl eax,esp # set stack pointer - movl eax,ebp # set base pointer -/* - * Zero out the BSS segment - */ -SYM (zero_bss): - cld # make direction flag count up - movl $ SYM (end),ecx # find end of .bss - movl $ SYM (_bss_start),edi # edi = beginning of .bss - subl edi,ecx # ecx = size of .bss in bytes - shrl ecx # size of .bss in longs - shrl ecx - xorl eax,eax # value to clear out memory - repne # while ecx != 0 - stosl # clear a long in the bss - -/* - * Copy the Global Descriptor Table to our space - */ - - sgdt SYM (_Original_GDTR) # save original GDT - movzwl SYM (_Original_GDTR)+DTR_LIMIT,ecx - /* size of GDT in bytes; limit is */ - /* 8192 entries * 8 bytes per */ - - /* - * make ds:esi point to the original GDT - */ - - movl SYM (_Original_GDTR)+DTR_BASE,esi - push ds # save ds - movw gs,ax - movw ax,ds - - /* - * make es:edi point to the new (our copy) GDT - */ - - movl $ SYM (_Global_descriptor_table),edi - - rep - movsb # copy the GDT (ds:esi -> es:edi) - - pop ds # restore ds - - /* - * Build and load new contents of GDTR - */ - movw SYM (_Original_GDTR)+DTR_LIMIT,ecx # set new limit - movw cx, SYM (_New_GDTR)+DTR_LIMIT - - push $ SYM (_Global_descriptor_table) - push es - call SYM (i386_Logical_to_physical) - addl $6,esp - movl eax, SYM (_New_GDTR)+DTR_BASE # set new base - - cmpb $0, SYM (_Do_Load_GDT) # Should the new GDT be loaded? - je SYM (no_gdt_load) # NO, then branch - lgdt SYM (_New_GDTR) # load the new GDT -SYM (no_gdt_load): - -/* - * Copy the Interrupt Descriptor Table to our space - */ - - sidt SYM (_Original_IDTR) # save original IDT - movzwl SYM (_Original_IDTR)+DTR_LIMIT,ecx - /* size of IDT in bytes; limit is */ - /* 256 entries * 8 bytes per */ - - - /* - * make ds:esi point to the original IDT - */ - movl SYM (_Original_IDTR)+DTR_BASE,esi - - push ds # save ds - movw gs,ax - movw ax,ds - - /* - * make es:edi point to the new (our copy) IDT - */ - movl $ SYM (Interrupt_descriptor_table),edi - - rep - movsb # copy the IDT (ds:esi -> es:edi) - pop ds # restore ds - - /* - * Build and load new contents of IDTR - */ - movw SYM (_Original_IDTR+DTR_LIMIT),ecx # set new limit - movw cx,SYM (_New_IDTR)+DTR_LIMIT - - push $ SYM (Interrupt_descriptor_table) - push es - call SYM (i386_Logical_to_physical) - addl $6,esp - movl eax, SYM (_New_IDTR)+DTR_BASE # set new base - - cmpb $0, SYM (_Do_Load_IDT) # Should the new IDT be loaded? - je SYM (no_idt_load) # NO, then branch - lidt SYM (_New_IDTR) # load the new IDT -SYM (no_idt_load): - -/* - * Initialize the i387. - * - * Using the NO WAIT form of the instruction insures that - * if it is not present the board will not lock up or get an - * exception. - */ - - fninit # MUST USE NO-WAIT FORM - -/* - * Transfer control to User's Board Support Package - */ - pushl $0 # environp - pushl $0 # argv - pushl $0 # argc - call SYM (boot_card) - addl $12,esp - -/* - * Clean up - */ - - EXTERN (return_to_monitor) - - PUBLIC (Bsp_cleanup) -SYM (Bsp_cleanup): - cmpb $0, SYM (_Do_Load_IDT) # Was the new IDT loaded? - je SYM (no_idt_restore) # NO, then branch - lidt SYM (_Original_IDTR) # restore the new IDT -SYM (no_idt_restore): - - cmpb $0, SYM (_Do_Load_GDT) # Was the new GDT loaded? - je SYM (no_gdt_restore) # NO, then branch - lgdt SYM (_Original_GDTR) # restore the new GDT -SYM (no_gdt_restore): - jmp SYM (_return_to_monitor) - -END_CODE - -BEGIN_DATA - - .align 2 - PUBLIC (start_frame) -SYM (start_frame): - .long 0 - - PUBLIC (stack_start) -SYM (stack_start): - .long 0 - -END_DATA - -BEGIN_BSS - - PUBLIC(heap_size) - .set heap_size,0x2000 - - PUBLIC(stack_size) - .set stack_size,0x1000 - - PUBLIC (Interrupt_descriptor_table) -SYM (Interrupt_descriptor_table): - .space 256*8 - - PUBLIC (_Original_IDTR) -SYM (_Original_IDTR): - .space DTR_SIZE - - PUBLIC (_New_IDTR) -SYM (_New_IDTR): - .space DTR_SIZE - - PUBLIC (_Global_descriptor_table) -SYM (_Global_descriptor_table): - .space 8192*8 - - PUBLIC (_Original_GDTR) -SYM (_Original_GDTR): - .space DTR_SIZE - - PUBLIC (_New_GDTR) -SYM (_New_GDTR): - .space DTR_SIZE - - PUBLIC (_Physical_base_of_ds) -SYM (_Physical_base_of_ds): - .space 4 - - PUBLIC (_Physical_base_of_cs) -SYM (_Physical_base_of_cs): - .space 4 - -END_BSS -END |