mirror of
https://github.com/torvalds/linux.git
synced 2024-11-07 12:41:55 +00:00
e03167b26b
Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
163 lines
4.2 KiB
ArmAsm
163 lines
4.2 KiB
ArmAsm
/*
|
|
* Early kernel startup code for Hexagon
|
|
*
|
|
* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
|
|
*
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/init.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/mem-layout.h>
|
|
#include <asm/vm_mmu.h>
|
|
#include <asm/page.h>
|
|
|
|
__INIT
|
|
ENTRY(stext)
|
|
/*
|
|
* VMM will already have set up true vector page, MMU, etc.
|
|
* To set up initial kernel identity map, we have to pass
|
|
* the VMM a pointer to some canonical page tables. In
|
|
* this implementation, we're assuming that we've got
|
|
* them precompiled. Generate value in R24, as we'll need
|
|
* it again shortly.
|
|
*/
|
|
r24.L = #LO(swapper_pg_dir)
|
|
r24.H = #HI(swapper_pg_dir)
|
|
|
|
/*
|
|
* Symbol is kernel segment address, but we need
|
|
* the logical/physical address.
|
|
*/
|
|
r24 = asl(r24, #2)
|
|
r24 = lsr(r24, #2)
|
|
|
|
r0 = r24
|
|
|
|
/*
|
|
* Initialize a 16MB PTE to make the virtual and physical
|
|
* addresses where the kernel was loaded be identical.
|
|
*/
|
|
#define PTE_BITS ( __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X \
|
|
| __HEXAGON_C_WB_L2 << 6 \
|
|
| __HVM_PDE_S_4MB)
|
|
|
|
r1 = pc
|
|
r2.H = #0xffc0
|
|
r2.L = #0x0000
|
|
r1 = and(r1,r2) /* round PC to 4MB boundary */
|
|
r2 = lsr(r1, #22) /* 4MB page number */
|
|
r2 = asl(r2, #2) /* times sizeof(PTE) (4bytes) */
|
|
r0 = add(r0,r2) /* r0 = address of correct PTE */
|
|
r2 = #PTE_BITS
|
|
r1 = add(r1,r2) /* r1 = 4MB PTE for the first entry */
|
|
r2.h = #0x0040
|
|
r2.l = #0x0000 /* 4MB */
|
|
memw(r0 ++ #4) = r1
|
|
r1 = add(r1, r2)
|
|
memw(r0 ++ #4) = r1
|
|
|
|
r0 = r24
|
|
|
|
/*
|
|
* The subroutine wrapper around the virtual instruction touches
|
|
* no memory, so we should be able to use it even here.
|
|
*/
|
|
call __vmnewmap;
|
|
|
|
/* Jump into virtual address range. */
|
|
|
|
r31.h = #hi(__head_s_vaddr_target)
|
|
r31.l = #lo(__head_s_vaddr_target)
|
|
jumpr r31
|
|
|
|
/* Insert trippy space effects. */
|
|
|
|
__head_s_vaddr_target:
|
|
/*
|
|
* Tear down VA=PA translation now that we are running
|
|
* in the desgnated kernel segments.
|
|
*/
|
|
r0 = #__HVM_PDE_S_INVALID
|
|
r1 = r24
|
|
loop0(1f,#0x100)
|
|
1:
|
|
{
|
|
memw(R1 ++ #4) = R0
|
|
}:endloop0
|
|
|
|
r0 = r24
|
|
call __vmnewmap
|
|
|
|
/* Go ahead and install the trap0 return so angel calls work */
|
|
r0.h = #hi(_K_provisional_vec)
|
|
r0.l = #lo(_K_provisional_vec)
|
|
call __vmsetvec
|
|
|
|
/*
|
|
* OK, at this point we should start to be much more careful,
|
|
* we're going to enter C code and start touching memory
|
|
* in all sorts of places.
|
|
* This means:
|
|
* SGP needs to be OK
|
|
* Need to lock shared resources
|
|
* A bunch of other things that will cause
|
|
* all kinds of painful bugs
|
|
*/
|
|
|
|
/*
|
|
* Stack pointer should be pointed at the init task's
|
|
* thread stack, which should have been declared in arch/init_task.c.
|
|
* So uhhhhh...
|
|
* It's accessible via the init_thread_union, which is a union
|
|
* of a thread_info struct and a stack; of course, the top
|
|
* of the stack is not for you. The end of the stack
|
|
* is simply init_thread_union + THREAD_SIZE.
|
|
*/
|
|
|
|
{r29.H = #HI(init_thread_union); r0.H = #HI(_THREAD_SIZE); }
|
|
{r29.L = #LO(init_thread_union); r0.L = #LO(_THREAD_SIZE); }
|
|
|
|
/* initialize the register used to point to current_thread_info */
|
|
/* Fixme: THREADINFO_REG can't be R2 because of that memset thing. */
|
|
{r29 = add(r29,r0); THREADINFO_REG = r29; }
|
|
|
|
/* Hack: zero bss; */
|
|
{ r0.L = #LO(__bss_start); r1 = #0; r2.l = #LO(__bss_stop); }
|
|
{ r0.H = #HI(__bss_start); r2.h = #HI(__bss_stop); }
|
|
|
|
r2 = sub(r2,r0);
|
|
call memset;
|
|
|
|
/* Time to make the doughnuts. */
|
|
call start_kernel
|
|
|
|
/*
|
|
* Should not reach here.
|
|
*/
|
|
1:
|
|
jump 1b
|
|
|
|
.p2align PAGE_SHIFT
|
|
ENTRY(external_cmdline_buffer)
|
|
.fill _PAGE_SIZE,1,0
|
|
|
|
.data
|
|
.p2align PAGE_SHIFT
|
|
ENTRY(empty_zero_page)
|
|
.fill _PAGE_SIZE,1,0
|