linux/arch/xtensa/boot/boot-redboot/bootstrap.S
Chris Zankel 367b8112fe xtensa: move headers files to arch/xtensa/include
Move all header files for xtensa to arch/xtensa/include and platform and
variant header files to the appropriate arch/xtensa/platforms/ and
arch/xtensa/variants/ directories.

Moving the files gets also rid of all uses of symlinks in the Makefile.

This has been completed already for the majority of the architectures
and xtensa is one out of six missing.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Chris Zankel <chris@zankel.net>
2008-11-06 10:25:09 -08:00

260 lines
4.7 KiB
ArmAsm

#include <variant/core.h>
#include <asm/regs.h>
#include <asm/asmmacro.h>
#include <asm/cacheasm.h>
/*
* RB-Data: RedBoot data/bss
* P: Boot-Parameters
* L: Kernel-Loader
*
* The Linux-Kernel image including the loader must be loaded
* to a position so that the kernel and the boot parameters
* can fit in the space before the load address.
* ______________________________________________________
* |_RB-Data_|_P_|__________|_L_|___Linux-Kernel___|______|
* ^
* ^ Load address
* ______________________________________________________
* |___Linux-Kernel___|_P_|_L_|___________________________|
*
* The loader copies the parameter to the position that will
* be the end of the kernel and itself to the end of the
* parameter list.
*/
/* Make sure we have enough space for the 'uncompressor' */
#define STACK_SIZE 32768
#define HEAP_SIZE (131072*4)
# a2: Parameter list
# a3: Size of parameter list
.section .start, "ax"
.globl __start
/* this must be the first byte of the loader! */
__start:
entry sp, 32 # we do not intend to return
_call0 _start
__start_a0:
.align 4
.section .text, "ax"
.begin literal_prefix .text
/* put literals in here! */
.globl _start
_start:
/* 'reset' window registers */
movi a4, 1
wsr a4, PS
rsync
rsr a5, WINDOWBASE
ssl a5
sll a4, a4
wsr a4, WINDOWSTART
rsync
movi a4, 0x00040000
wsr a4, PS
rsync
/* copy the loader to its address
* Note: The loader itself is a very small piece, so we assume we
* don't partially overlap. We also assume (even more important)
* that the kernel image is out of the way. Usually, when the
* load address of this image is not at an arbitrary address,
* but aligned to some 10K's we shouldn't overlap.
*/
/* Note: The assembler cannot relax "addi a0, a0, ..." to an
l32r, so we load to a4 first. */
# addi a4, a0, __start - __start_a0
# mov a0, a4
movi a4, __start
movi a5, __start_a0
add a4, a0, a4
sub a0, a4, a5
movi a4, __start
movi a5, __reloc_end
# a0: address where this code has been loaded
# a4: compiled address of __start
# a5: compiled end address
mov.n a7, a0
mov.n a8, a4
1:
l32i a10, a7, 0
l32i a11, a7, 4
s32i a10, a8, 0
s32i a11, a8, 4
l32i a10, a7, 8
l32i a11, a7, 12
s32i a10, a8, 8
s32i a11, a8, 12
addi a8, a8, 16
addi a7, a7, 16
blt a8, a5, 1b
/* We have to flush and invalidate the caches here before we jump. */
#if XCHAL_DCACHE_IS_WRITEBACK
___flush_dcache_all a5 a6
#endif
___invalidate_icache_all a5 a6
isync
movi a11, _reloc
jx a11
.globl _reloc
_reloc:
/* RedBoot is now at the end of the memory, so we don't have
* to copy the parameter list. Keep the code around; in case
* we need it again. */
#if 0
# a0: load address
# a2: start address of parameter list
# a3: length of parameter list
# a4: __start
/* copy the parameter list out of the way */
movi a6, _param_start
add a3, a2, a3
2:
l32i a8, a2, 0
s32i a8, a6, 0
addi a2, a2, 4
addi a6, a6, 4
blt a2, a3, 2b
#endif
/* clear BSS section */
movi a6, __bss_start
movi a7, __bss_end
movi.n a5, 0
3:
s32i a5, a6, 0
addi a6, a6, 4
blt a6, a7, 3b
movi a5, -16
movi a1, _stack + STACK_SIZE
and a1, a1, a5
/* Uncompress the kernel */
# a0: load address
# a2: boot parameter
# a4: __start
movi a3, __image_load
sub a4, a3, a4
add a8, a0, a4
# a1 Stack
# a8(a4) Load address of the image
movi a6, _image_start
movi a10, _image_end
movi a7, 0x1000000
sub a11, a10, a6
movi a9, complen
s32i a11, a9, 0
movi a0, 0
# a6 destination
# a7 maximum size of destination
# a8 source
# a9 ptr to length
.extern gunzip
movi a4, gunzip
beqz a4, 1f
callx4 a4
j 2f
# a6 destination start
# a7 maximum size of destination
# a8 source start
# a9 ptr to length
# a10 destination end
1:
l32i a9, a8, 0
l32i a11, a8, 4
s32i a9, a6, 0
s32i a11, a6, 4
l32i a9, a8, 8
l32i a11, a8, 12
s32i a9, a6, 8
s32i a11, a6, 12
addi a6, a6, 16
addi a8, a8, 16
blt a6, a10, 1b
/* jump to the kernel */
2:
#if XCHAL_DCACHE_IS_WRITEBACK
___flush_dcache_all a5 a6
#endif
___invalidate_icache_all a5 a6
isync
movi a5, __start
movi a3, boot_initrd_start
movi a4, boot_initrd_end
sub a3, a3, a5
sub a4, a4, a5
add a3, a0, a3
add a4, a0, a4
# a2 Boot parameter list
# a3 initrd_start (virtual load address)
# a4 initrd_end (virtual load address)
movi a0, _image_start
jx a0
.align 16
.data
.globl avail_ram
avail_ram:
.long _heap
.globl end_avail
end_avail:
.long _heap + HEAP_SIZE
.comm _stack, STACK_SIZE
.comm _heap, HEAP_SIZE
.globl end_avail
.comm complen, 4
.end literal_prefix