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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
.section .init.text
.global start
start:
/* We begin with some tricks. If we have built our code to be loaded
* via the standalone GDB stub, we will have out VBR at some other
* location than 0x9000000. We must copy the trap vectors for the
* GDB stub to our vector table.
* If, on the other hand, we are running standalone we will have
* the VBR at 0x9000000, and the copy will not do any harm.
*/
mov.l vbr_k,r1
mov.l orig_vbr_k,r2
/* Move the invalid instruction vector (4) */
mov #4,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the invalid slot vector (6) */
mov #6,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the bus error vector (9) */
mov #9,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the DMA bus error vector (10) */
mov #10,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the NMI vector as well (11) */
mov #11,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the breakpoint trap vector (32) */
mov #32,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the IO trap vector (33) */
mov #33,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the serial Rx interrupt vector (105) */
mov #105,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
/* Move the single step trap vector (127) */
mov #127,r0
shll2 r0
mov.l @(r0,r2),r3
mov.l r3,@(r0,r1)
ldc r1,vbr
/* Now let's get on with the normal business */
mov.l stack_k,r15
/* zero out bss */
mov.l edata_k,r0
mov.l end_k,r1
mov #0,r2
start_l:
mov.l r2,@r0
add #4,r0
cmp/ge r1,r0
bf start_l
nop
/* copy the .iram section */
mov.l iramcopy_k,r0
mov.l iram_k,r1
mov.l iramend_k,r2
copy_l:
mov.l @r0,r3
mov.l r3,@r1
add #4,r0
add #4,r1
cmp/ge r2,r1
bf copy_l
nop
/* copy the .data section, for rombased execution */
mov.l datacopy_k,r0
mov.l data_k,r1
mov.l dataend_k,r2
/* Don't copy if src and dest are equal */
cmp/eq r0,r1
bt nodatacopy
copy_l2:
mov.l @r0,r3
mov.l r3,@r1
add #4,r0
add #4,r1
cmp/ge r2,r1
bf copy_l2
nop
nodatacopy:
/* Munge the main thread stack */
mov.l stack_k,r2
mov.l deadbeef_k,r0
mov.l stackbegin_k,r1
munge_loop:
mov.l r0,@r1
add #4,r1
cmp/ge r2,r1
bf munge_loop
nop
mov #0,r0
ldc r0,gbr
! call the mainline
mov.l main_k,r0
jsr @r0
nop
.hoo:
bra .hoo
.align 2
stack_k:
.long _stackend
stackbegin_k:
.long _stackbegin
deadbeef_k:
.long 0xdeadbeef
edata_k:
.long _edata
end_k:
.long _end
iramcopy_k:
.long _iramcopy
iram_k:
.long _iramstart
iramend_k:
.long _iramend
datacopy_k:
.long _datacopy
data_k:
.long _datastart
dataend_k:
.long _dataend
main_k:
.long _main
vbr_k:
.long vectors
orig_vbr_k:
.long 0x9000000
.section .resetvectors
vectors:
.long start
.long _stackend
.long start
.long _stackend
|
