1 files changed, 165 insertions, 0 deletions
diff --git a/bl1/aarch32/bl1_exceptions.S b/bl1/aarch32/bl1_exceptions.S
new file mode 100644
index 0000000..4a6815f
--- /dev/null
+++ b/bl1/aarch32/bl1_exceptions.S
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <bl1/bl1.h>
+#include <common/bl_common.h>
+#include <context.h>
+#include <lib/xlat_tables/xlat_tables.h>
+#include <smccc_helpers.h>
+#include <smccc_macros.S>
+
+	.globl	bl1_aarch32_smc_handler
+
+
+func bl1_aarch32_smc_handler
+	/* On SMC entry, `sp` points to `smc_ctx_t`. Save `lr`. */
+	str	lr, [sp, #SMC_CTX_LR_MON]
+
+	/* ------------------------------------------------
+	 * SMC in BL1 is handled assuming that the MMU is
+	 * turned off by BL2.
+	 * ------------------------------------------------
+	 */
+
+	/* ----------------------------------------------
+	 * Detect if this is a RUN_IMAGE or other SMC.
+	 * ----------------------------------------------
+	 */
+	mov	lr, #BL1_SMC_RUN_IMAGE
+	cmp	lr, r0
+	bne	smc_handler
+
+	/* ------------------------------------------------
+	 * Make sure only Secure world reaches here.
+	 * ------------------------------------------------
+	 */
+	ldcopr  r8, SCR
+	tst	r8, #SCR_NS_BIT
+	blne	report_exception
+
+	/* ---------------------------------------------------------------------
+	 * Pass control to next secure image.
+	 * Here it expects r1 to contain the address of a entry_point_info_t
+	 * structure describing the BL entrypoint.
+	 * ---------------------------------------------------------------------
+	 */
+	mov	r8, r1
+	mov	r0, r1
+	bl	bl1_print_next_bl_ep_info
+
+#if SPIN_ON_BL1_EXIT
+	bl	print_debug_loop_message
+debug_loop:
+	b	debug_loop
+#endif
+
+	mov	r0, r8
+	bl	bl1_plat_prepare_exit
+
+	stcopr	r0, TLBIALL
+	dsb	sy
+	isb
+
+	/*
+	 * Extract PC and SPSR based on struct `entry_point_info_t`
+	 * and load it in LR and SPSR registers respectively.
+	 */
+	ldr	lr, [r8, #ENTRY_POINT_INFO_PC_OFFSET]
+	ldr	r1, [r8, #(ENTRY_POINT_INFO_PC_OFFSET + 4)]
+	msr	spsr_xc, r1
+
+	/* Some BL32 stages expect lr_svc to provide the BL33 entry address */
+	cps	#MODE32_svc
+	ldr	lr, [r8, #ENTRY_POINT_INFO_LR_SVC_OFFSET]
+	cps	#MODE32_mon
+
+	add	r8, r8, #ENTRY_POINT_INFO_ARGS_OFFSET
+	ldm	r8, {r0, r1, r2, r3}
+	exception_return
+endfunc bl1_aarch32_smc_handler
+
+	/* -----------------------------------------------------
+	 * Save Secure/Normal world context and jump to
+	 * BL1 SMC handler.
+	 * -----------------------------------------------------
+	 */
+func smc_handler
+	/* -----------------------------------------------------
+	 * Save the GP registers.
+	 * -----------------------------------------------------
+	 */
+	smccc_save_gp_mode_regs
+
+	/*
+	 * `sp` still points to `smc_ctx_t`. Save it to a register
+	 * and restore the C runtime stack pointer to `sp`.
+	 */
+	mov	r6, sp
+	ldr	sp, [r6, #SMC_CTX_SP_MON]
+
+	ldr	r0, [r6, #SMC_CTX_SCR]
+	and	r7, r0, #SCR_NS_BIT		/* flags */
+
+	/* Switch to Secure Mode */
+	bic	r0, #SCR_NS_BIT
+	stcopr	r0, SCR
+	isb
+
+	/* If caller is from Secure world then turn on the MMU */
+	tst	r7, #SCR_NS_BIT
+	bne	skip_mmu_on
+
+	/* Turn on the MMU */
+	mov	r0, #DISABLE_DCACHE
+	bl	enable_mmu_svc_mon
+
+	/*
+	 * Invalidate `smc_ctx_t` in data cache to prevent dirty data being
+	 * used.
+	 */
+	mov	r0, r6
+	mov	r1, #SMC_CTX_SIZE
+	bl	inv_dcache_range
+
+	/* Enable the data cache. */
+	ldcopr	r9, SCTLR
+	orr	r9, r9, #SCTLR_C_BIT
+	stcopr	r9, SCTLR
+	isb
+
+skip_mmu_on:
+	/* Prepare arguments for BL1 SMC wrapper. */
+	ldr	r0, [r6, #SMC_CTX_GPREG_R0]	/* smc_fid */
+	mov	r1, #0				/* cookie */
+	mov	r2, r6				/* handle */
+	mov	r3, r7				/* flags */
+	bl	bl1_smc_wrapper
+
+	/* Get the smc_context for next BL image */
+	bl	smc_get_next_ctx
+	mov	r4, r0
+
+	/* Only turn-off MMU if going to secure world */
+	ldr	r5, [r4, #SMC_CTX_SCR]
+	tst	r5, #SCR_NS_BIT
+	bne	skip_mmu_off
+
+	/* Disable the MMU */
+	bl	disable_mmu_icache_secure
+	stcopr	r0, TLBIALL
+	dsb	sy
+	isb
+
+skip_mmu_off:
+	/* -----------------------------------------------------
+	 * Do the transition to next BL image.
+	 * -----------------------------------------------------
+	 */
+	mov	r0, r4
+	monitor_exit
+endfunc smc_handler