plat: imx: common: implement IMX_SIP_AARCH32

Implement IMX_SIP_AARCH32 to let AArch64 Bootloader could issue
SIP call to switch to AArch32 mode to run OS.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Change-Id: I38b04ef909a6dbfba5ded12a7bb6e799a3935a66

plat/imx/common/imx_sip_handler.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <arch.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <services/std_svc.h>
@@ -12,6 +13,7 @@
 #include <common/debug.h>
 #include <common/runtime_svc.h>
 #include <imx_sip_svc.h>
+#include <lib/el3_runtime/context_mgmt.h>
 #include <sci/sci.h>
 
 #if defined(PLAT_imx8qm) || defined(PLAT_imx8qx)
@@ -185,3 +187,37 @@ uint64_t imx_buildinfo_handler(uint32_t smc_fid,
 
 	return ret;
 }
+
+int imx_kernel_entry_handler(uint32_t smc_fid,
+		u_register_t x1,
+		u_register_t x2,
+		u_register_t x3,
+		u_register_t x4)
+{
+	static entry_point_info_t bl33_image_ep_info;
+	entry_point_info_t *next_image_info;
+	unsigned int mode;
+
+	if (x1 < (PLAT_NS_IMAGE_OFFSET & 0xF0000000))
+		return SMC_UNK;
+
+	mode = MODE32_svc;
+
+	next_image_info = &bl33_image_ep_info;
+
+	next_image_info->pc = x1;
+
+	next_image_info->spsr = SPSR_MODE32(mode, SPSR_T_ARM, SPSR_E_LITTLE,
+			(DAIF_FIQ_BIT | DAIF_IRQ_BIT | DAIF_ABT_BIT));
+
+	next_image_info->args.arg0 = 0;
+	next_image_info->args.arg1 = 0;
+	next_image_info->args.arg2 = x3;
+
+	SET_SECURITY_STATE(next_image_info->h.attr, NON_SECURE);
+
+	cm_init_my_context(next_image_info);
+	cm_prepare_el3_exit(NON_SECURE);
+
+	return 0;
+}

plat/imx/common/imx_sip_svc.c

@@ -26,6 +26,9 @@ static uintptr_t imx_sip_handler(unsigned int smc_fid,
 			u_register_t flags)
 {
 	switch (smc_fid) {
+	case IMX_SIP_AARCH32:
+		SMC_RET1(handle, imx_kernel_entry_handler(smc_fid, x1, x2, x3, x4));
+		break;
 #if defined(PLAT_imx8mq)
 	case IMX_SIP_GET_SOC_INFO:
 		SMC_RET1(handle, imx_soc_info_handler(smc_fid, x1, x2, x3));

plat/imx/common/include/imx_sip_svc.h

@@ -28,6 +28,11 @@
 
 #define IMX_SIP_MISC_SET_TEMP		0xC200000C
 
+#define IMX_SIP_AARCH32			0xC20000FD
+
+int imx_kernel_entry_handler(uint32_t smc_fid, u_register_t x1,
+			     u_register_t x2, u_register_t x3,
+			     u_register_t x4);
 #if defined(PLAT_imx8mq)
 int imx_soc_info_handler(uint32_t smc_fid, u_register_t x1,
 			 u_register_t x2, u_register_t x3);