arm-trusted-firmware/lib/aarch32/misc_helpers.S
Yatharth Kochar 1a0a3f0622 AArch32: Common changes needed for BL1/BL2
This patch adds common changes to support AArch32 state in
BL1 and BL2. Following are the changes:

* Added functions for disabling MMU from Secure state.
* Added AArch32 specific SMC function.
* Added semihosting support.
* Added reporting of unhandled exceptions.
* Added uniprocessor stack support.
* Added `el3_entrypoint_common` macro that can be
  shared by BL1 and BL32 (SP_MIN) BL stages. The
  `el3_entrypoint_common` is similar to the AArch64
  counterpart with the main difference in the assembly
  instructions and the registers that are relevant to
  AArch32 execution state.
* Enabled `LOAD_IMAGE_V2` flag in Makefile for
  `ARCH=aarch32` and added check to make sure that
  platform has not overridden to disable it.

Change-Id: I33c6d8dfefb2e5d142fdfd06a0f4a7332962e1a3
2016-09-21 16:27:15 +01:00

96 lines
3 KiB
ArmAsm

/*
* Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#include <asm_macros.S>
#include <assert_macros.S>
.globl smc
.globl zeromem
.globl disable_mmu_icache_secure
.globl disable_mmu_secure
func smc
/*
* For AArch32 only r0-r3 will be in the registers;
* rest r4-r6 will be pushed on to the stack. So here, we'll
* have to load them from the stack to registers r4-r6 explicitly.
* Clobbers: r4-r6
*/
ldm sp, {r4, r5, r6}
smc #0
endfunc smc
/* -----------------------------------------------------------------------
* void zeromem(void *mem, unsigned int length);
*
* Initialise a memory region to 0.
* The memory address and length must be 4-byte aligned.
* -----------------------------------------------------------------------
*/
func zeromem
#if ASM_ASSERTION
tst r0, #0x3
ASM_ASSERT(eq)
tst r1, #0x3
ASM_ASSERT(eq)
#endif
add r2, r0, r1
mov r1, #0
z_loop:
cmp r2, r0
beq z_end
str r1, [r0], #4
b z_loop
z_end:
bx lr
endfunc zeromem
/* ---------------------------------------------------------------------------
* Disable the MMU in Secure State
* ---------------------------------------------------------------------------
*/
func disable_mmu_secure
mov r1, #(SCTLR_M_BIT | SCTLR_C_BIT)
do_disable_mmu:
ldcopr r0, SCTLR
bic r0, r0, r1
stcopr r0, SCTLR
isb // ensure MMU is off
dsb sy
bx lr
endfunc disable_mmu_secure
func disable_mmu_icache_secure
ldr r1, =(SCTLR_M_BIT | SCTLR_C_BIT | SCTLR_I_BIT)
b do_disable_mmu
endfunc disable_mmu_icache_secure