glibc/sysdeps/standalone/i386/start.S
Roland McGrath 0bec0145c4 2004-08-15 Roland McGrath <roland@frob.com>
* csu/elf-init.c: Update copyright terms including special exception
	for these trivial files, which are statically linked into executables
	that use dynamic linking for the significant library code.
	* io/fstat.c: Likewise.
	* io/fstat64.c: Likewise.
	* io/lstat.c: Likewise.
	* io/lstat64.c: Likewise.
	* io/stat.c: Likewise.
	* io/stat64.c: Likewise.
	* stdlib/atexit.c: Likewise.
	* sysdeps/alpha/elf/initfini.c: Likewise.
	* sysdeps/alpha/elf/start.S: Likewise.
	* sysdeps/arm/elf/start.S: Likewise.
	* sysdeps/cris/elf/start.S: Likewise.
	* sysdeps/generic/initfini.c: Likewise.
	* sysdeps/generic/mknod.c: Likewise.
	* sysdeps/hppa/elf/initfini.c: Likewise.
	* sysdeps/hppa/elf/start.S: Likewise.
	* sysdeps/i386/elf/start.S: Likewise.
	* sysdeps/i386/i686/hp-timing.c: Likewise.
	* sysdeps/ia64/elf/initfini.c: Likewise.
	* sysdeps/ia64/elf/start.S: Likewise.
	* sysdeps/ia64/hp-timing.c: Likewise.
	* sysdeps/m68k/elf/start.S: Likewise.
	* sysdeps/mach/start.c: Likewise.
	* sysdeps/mips/elf/start.S: Likewise.
	* sysdeps/powerpc/powerpc32/elf/start.S: Likewise.
	* sysdeps/powerpc/powerpc64/elf/start.S: Likewise.
	* sysdeps/s390/s390-32/elf/start.S: Likewise.
	* sysdeps/s390/s390-32/initfini.c: Likewise.
	* sysdeps/s390/s390-64/elf/start.S: Likewise.
	* sysdeps/s390/s390-64/initfini.c: Likewise.
	* sysdeps/sh/elf/initfini.c: Likewise.
	* sysdeps/sh/elf/start.S: Likewise.
	* sysdeps/sparc/sparc32/elf/start.S: Likewise.
	* sysdeps/sparc/sparc32/sparcv9/hp-timing.c: Likewise.
	* sysdeps/sparc/sparc64/elf/start.S: Likewise.
	* sysdeps/sparc/sparc64/hp-timing.c: Likewise.
	* sysdeps/standalone/i386/start.S: Likewise.
	* sysdeps/standalone/i960/start.S: Likewise.
	* sysdeps/standalone/m68k/m68020/start.S: Likewise.
	* sysdeps/unix/arm/start.c: Likewise.
	* sysdeps/unix/bsd/osf/alpha/start.S: Likewise.
	* sysdeps/unix/bsd/ultrix4/mips/start.S: Likewise.
	* sysdeps/unix/sparc/start.c: Likewise.
	* sysdeps/unix/start.c: Likewise.
	* sysdeps/unix/sysv/aix/start.s: Likewise.
	* sysdeps/unix/sysv/irix4/start.c: Likewise.
	* sysdeps/x86_64/elf/initfini.c: Likewise.
	* sysdeps/x86_64/elf/start.S: Likewise.
2004-08-16 04:51:04 +00:00

339 lines
9.6 KiB
ArmAsm

/* Copyright (C) 1994, 1997 Free Software Foundation, Inc.
Contributed by Joel Sherrill (jsherril@redstone-emh2.army.mil),
On-Line Applications Research Corporation.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* entry.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.
*
*/
.data
.global _Do_Load_IDT
.global _Do_Load_GDT
.text
.global start # GNU default entry point
.global _establish_stack
.global _bsp_start
.global _load_segments
.global __exit
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 _load_segments # load board dependent segments
#
# Set up the stack
#
_establish_stack:
movl $stack_end,%esp # set stack pointer
movl $stack_end,%ebp # set base pointer
#
# Zero out the BSS segment
#
zero_bss:
cld # make direction flag count up
movl $_end,%ecx # find end of .bss
movl $_bss_start,%edi # edi = beginning of .bss
subl %edi,%ecx # ecx = size of .bss in bytes
shrl $2,%ecx # size of .bss in longs
xorl %eax,%eax # value to clear out memory
repne # while ecx != 0
stosl # clear a long in the bss
#
# Set the C heap information for malloc
#
movl $heap_size,___C_heap_size # set ___C_heap_size
movl $heap_memory,___C_heap_start # set ___C_heap_start
#
# Copy the Global Descriptor Table to our space
#
sgdt _Original_GDTR # save original GDT
movzwl _Original_GDTR_limit,%ecx # size of GDT in bytes; limit
# is 8192 entries * 8 bytes per
# make ds:esi point to the original GDT
movl _Original_GDTR_base,%esi
push %ds # save ds
movw %gs,%ax
movw %ax,%ds
# make es:edi point to the new (our copy) GDT
movl $_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 _Original_GDTR_limit,%ecx # set new limit
movw %cx,_New_GDTR_limit
push $_Global_descriptor_table
push %es
call _Logical_to_physical
addl $6,%esp
movl %eax,_New_GDTR_base # set new base
cmpb $0,_Do_Load_GDT # Should the new GDT be loaded?
je no_gdt_load # NO, then branch
lgdt _New_GDTR # load the new GDT
no_gdt_load:
#
# Copy the Interrupt Descriptor Table to our space
#
sidt _Original_IDTR # save original IDT
movzwl _Original_IDTR_limit,%ecx # size of IDT in bytes; limit
# is 256 entries * 8 bytes per
# make ds:esi point to the original IDT
movl _Original_IDTR_base,%esi
push %ds # save ds
movw %gs,%ax
movw %ax,%ds
# make es:edi point to the new (our copy) IDT
movl $_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 _Original_IDTR_limit,%ecx # set new limit
movw %cx,_New_IDTR_limit
push $_Interrupt_descriptor_table
push %es
call _Logical_to_physical
addl $6,%esp
movl %eax,_New_IDTR_base # set new base
cmpb $0,_Do_Load_IDT # Should the new IDT be loaded?
je no_idt_load # NO, then branch
lidt _New_IDTR # load the new IDT
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
call __Board_Initialize # initialize the board
pushl $0 # envp = NULL
pushl $0 # argv = NULL
pushl $0 # argc = NULL
call ___libc_init # initialize the library and
# call main
addl $12,%esp
pushl $0 # argc = NULL
call __exit # call the Board specific exit
addl $4,%esp
#
# Clean up
#
.global _Bsp_cleanup
.global _return_to_monitor
_Bsp_cleanup:
cmpb $0,_Do_Load_IDT # Was the new IDT loaded?
je no_idt_restore # NO, then branch
lidt _Original_IDTR # restore the new IDT
no_idt_restore:
cmpb $0,_Do_Load_GDT # Was the new GDT loaded?
je no_gdt_restore # NO, then branch
lgdt _Original_GDTR # restore the new GDT
no_gdt_restore:
jmp _return_to_monitor
#
# void *Logical_to_physical(
# rtems_unsigned16 segment,
# void *address
# );
#
# Returns thirty-two bit physical address for segment:address.
#
.global _Logical_to_physical
.set SEGMENT_ARG, 4
.set ADDRESS_ARG, 8
_Logical_to_physical:
xorl %eax,%eax # clear eax
movzwl SEGMENT_ARG(%esp),%ecx # ecx = segment value
movl $_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 *Physical_to_logical(
# rtems_unsigned16 segment,
# void *address
# );
#
# Returns thirty-two bit physical address for segment:address.
#
.global _Physical_to_logical
#.set SEGMENT_ARG, 4
#.set ADDRESS_ARG, 8 -- use sets from above
_Physical_to_logical:
xorl %eax,%eax # clear eax
movzwl SEGMENT_ARG(%esp),%ecx # ecx = segment value
movl $_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
/*
* Data Declarations. Start with a macro which helps declare space.
*/
.bss
#define DECLARE_SPACE(_name,_space,_align) \
.globl _name ; \
.align _align ; \
_name##: .space _space
#define DECLARE_LABEL(_name) \
.globl _name ; \
_name##:
#define DECLARE_PTR(_name) DECLARE_SPACE(_name,4,2)
#define DECLARE_U32(_name) DECLARE_SPACE(_name,4,2)
#define DECLARE_U16(_name) DECLARE_SPACE(_name,2,1)
/*
* Require environment stuff
*/
DECLARE_LABEL(_environ)
DECLARE_PTR(environ)
DECLARE_LABEL(_errno)
DECLARE_U32(errno)
/*
* Miscellaneous Variables used to restore the CPU state.
*
* Start with a macro to declare the space for the contents of
* a Descriptor Table register.
*/
#define DECLARE_DTR_SPACE(_name) \
.global _name ; \
.align 4 ; \
_name##: ; \
_name##_limit: .space 2 ; \
_name##_base: .space 4
DECLARE_SPACE(_Interrupt_descriptor_table,256*8,4)
DECLARE_SPACE(_Global_descriptor_table,8192*8,4)
DECLARE_DTR_SPACE(_Original_IDTR)
DECLARE_DTR_SPACE(_New_IDTR)
DECLARE_DTR_SPACE(_Original_GDTR)
DECLARE_DTR_SPACE(_New_GDTR)
DECLARE_SPACE(_Physical_base_of_ds,4,4)
DECLARE_SPACE(_Physical_base_of_cs,4,4)
/*
* Stack Size and Space
*/
.set stack_size, 0x20000
DECLARE_SPACE(stack_memory,stack_size,4)
DECLARE_LABEL(stack_end)