switch-l4t-atf/bl31/bl31_main.c
davidcunado-arm d6104f5ab4 Merge pull request #927 from jeenu-arm/state-switch
Execution state switch
2017-05-11 16:04:52 +01:00

181 lines
6.2 KiB
C

/*
* Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <bl_common.h>
#include <bl31.h>
#include <console.h>
#include <context_mgmt.h>
#include <debug.h>
#include <platform.h>
#include <pmf.h>
#include <runtime_instr.h>
#include <runtime_svc.h>
#include <string.h>
#if ENABLE_RUNTIME_INSTRUMENTATION
PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
#endif
/*******************************************************************************
* This function pointer is used to initialise the BL32 image. It's initialized
* by SPD calling bl31_register_bl32_init after setting up all things necessary
* for SP execution. In cases where both SPD and SP are absent, or when SPD
* finds it impossible to execute SP, this pointer is left as NULL
******************************************************************************/
static int32_t (*bl32_init)(void);
/*******************************************************************************
* Variable to indicate whether next image to execute after BL31 is BL33
* (non-secure & default) or BL32 (secure).
******************************************************************************/
static uint32_t next_image_type = NON_SECURE;
/*
* Implement the ARM Standard Service function to get arguments for a
* particular service.
*/
uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
{
/* Setup the arguments for PSCI Library */
DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
/* PSCI is the only ARM Standard Service implemented */
assert(svc_mask == PSCI_FID_MASK);
return (uintptr_t)&psci_args;
}
/*******************************************************************************
* Simple function to initialise all BL31 helper libraries.
******************************************************************************/
void bl31_lib_init(void)
{
cm_init();
}
/*******************************************************************************
* BL31 is responsible for setting up the runtime services for the primary cpu
* before passing control to the bootloader or an Operating System. This
* function calls runtime_svc_init() which initializes all registered runtime
* services. The run time services would setup enough context for the core to
* swtich to the next exception level. When this function returns, the core will
* switch to the programmed exception level via. an ERET.
******************************************************************************/
void bl31_main(void)
{
NOTICE("BL31: %s\n", version_string);
NOTICE("BL31: %s\n", build_message);
/* Perform platform setup in BL31 */
bl31_platform_setup();
/* Initialise helper libraries */
bl31_lib_init();
/* Initialize the runtime services e.g. psci. */
INFO("BL31: Initializing runtime services\n");
runtime_svc_init();
/*
* All the cold boot actions on the primary cpu are done. We now need to
* decide which is the next image (BL32 or BL33) and how to execute it.
* If the SPD runtime service is present, it would want to pass control
* to BL32 first in S-EL1. In that case, SPD would have registered a
* function to intialize bl32 where it takes responsibility of entering
* S-EL1 and returning control back to bl31_main. Once this is done we
* can prepare entry into BL33 as normal.
*/
/*
* If SPD had registerd an init hook, invoke it.
*/
if (bl32_init) {
INFO("BL31: Initializing BL32\n");
(*bl32_init)();
}
/*
* We are ready to enter the next EL. Prepare entry into the image
* corresponding to the desired security state after the next ERET.
*/
bl31_prepare_next_image_entry();
console_flush();
/*
* Perform any platform specific runtime setup prior to cold boot exit
* from BL31
*/
bl31_plat_runtime_setup();
}
/*******************************************************************************
* Accessor functions to help runtime services decide which image should be
* executed after BL31. This is BL33 or the non-secure bootloader image by
* default but the Secure payload dispatcher could override this by requesting
* an entry into BL32 (Secure payload) first. If it does so then it should use
* the same API to program an entry into BL33 once BL32 initialisation is
* complete.
******************************************************************************/
void bl31_set_next_image_type(uint32_t security_state)
{
assert(sec_state_is_valid(security_state));
next_image_type = security_state;
}
uint32_t bl31_get_next_image_type(void)
{
return next_image_type;
}
/*******************************************************************************
* This function programs EL3 registers and performs other setup to enable entry
* into the next image after BL31 at the next ERET.
******************************************************************************/
void bl31_prepare_next_image_entry(void)
{
entry_point_info_t *next_image_info;
uint32_t image_type;
#if CTX_INCLUDE_AARCH32_REGS
/*
* Ensure that the build flag to save AArch32 system registers in CPU
* context is not set for AArch64-only platforms.
*/
if (EL_IMPLEMENTED(1) == EL_IMPL_A64ONLY) {
ERROR("EL1 supports AArch64-only. Please set build flag "
"CTX_INCLUDE_AARCH32_REGS = 0");
panic();
}
#endif
/* Determine which image to execute next */
image_type = bl31_get_next_image_type();
/* Program EL3 registers to enable entry into the next EL */
next_image_info = bl31_plat_get_next_image_ep_info(image_type);
assert(next_image_info);
assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
INFO("BL31: Preparing for EL3 exit to %s world\n",
(image_type == SECURE) ? "secure" : "normal");
print_entry_point_info(next_image_info);
cm_init_my_context(next_image_info);
cm_prepare_el3_exit(image_type);
}
/*******************************************************************************
* This function initializes the pointer to BL32 init function. This is expected
* to be called by the SPD after it finishes all its initialization
******************************************************************************/
void bl31_register_bl32_init(int32_t (*func)(void))
{
bl32_init = func;
}