| /* |
| * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <asm_macros.S> |
| #include "../spm_private.h" |
| |
| .global spm_secure_partition_enter |
| .global spm_secure_partition_exit |
| |
| /* --------------------------------------------------------------------- |
| * This function is called with SP_EL0 as stack. Here we stash our EL3 |
| * callee-saved registers on to the stack as a part of saving the C |
| * runtime and enter the secure payload. |
| * 'x0' contains a pointer to the memory where the address of the C |
| * runtime context is to be saved. |
| * --------------------------------------------------------------------- |
| */ |
| func spm_secure_partition_enter |
| /* Make space for the registers that we're going to save */ |
| mov x3, sp |
| str x3, [x0, #0] |
| sub sp, sp, #SP_C_RT_CTX_SIZE |
| |
| /* Save callee-saved registers on to the stack */ |
| stp x19, x20, [sp, #SP_C_RT_CTX_X19] |
| stp x21, x22, [sp, #SP_C_RT_CTX_X21] |
| stp x23, x24, [sp, #SP_C_RT_CTX_X23] |
| stp x25, x26, [sp, #SP_C_RT_CTX_X25] |
| stp x27, x28, [sp, #SP_C_RT_CTX_X27] |
| stp x29, x30, [sp, #SP_C_RT_CTX_X29] |
| |
| /* --------------------------------------------------------------------- |
| * Everything is setup now. el3_exit() will use the secure context to |
| * restore to the general purpose and EL3 system registers to ERET |
| * into the secure payload. |
| * --------------------------------------------------------------------- |
| */ |
| b el3_exit |
| endfunc spm_secure_partition_enter |
| |
| /* --------------------------------------------------------------------- |
| * This function is called with 'x0' pointing to a C runtime context |
| * saved in spm_secure_partition_enter(). |
| * It restores the saved registers and jumps to that runtime with 'x0' |
| * as the new SP register. This destroys the C runtime context that had |
| * been built on the stack below the saved context by the caller. Later |
| * the second parameter 'x1' is passed as a return value to the caller. |
| * --------------------------------------------------------------------- |
| */ |
| func spm_secure_partition_exit |
| /* Restore the previous stack */ |
| mov sp, x0 |
| |
| /* Restore callee-saved registers on to the stack */ |
| ldp x19, x20, [x0, #(SP_C_RT_CTX_X19 - SP_C_RT_CTX_SIZE)] |
| ldp x21, x22, [x0, #(SP_C_RT_CTX_X21 - SP_C_RT_CTX_SIZE)] |
| ldp x23, x24, [x0, #(SP_C_RT_CTX_X23 - SP_C_RT_CTX_SIZE)] |
| ldp x25, x26, [x0, #(SP_C_RT_CTX_X25 - SP_C_RT_CTX_SIZE)] |
| ldp x27, x28, [x0, #(SP_C_RT_CTX_X27 - SP_C_RT_CTX_SIZE)] |
| ldp x29, x30, [x0, #(SP_C_RT_CTX_X29 - SP_C_RT_CTX_SIZE)] |
| |
| /* --------------------------------------------------------------------- |
| * This should take us back to the instruction after the call to the |
| * last spm_secure_partition_enter().* Place the second parameter to x0 |
| * so that the caller will see it as a return value from the original |
| * entry call. |
| * --------------------------------------------------------------------- |
| */ |
| mov x0, x1 |
| ret |
| endfunc spm_secure_partition_exit |
