MLK-13450-7 mx7ulp: Add M4 core boot support when using single boot mode

The single boot mode in MX7ULP will only boot up A7, the M4 is running in ROM
by checking entry from SIM0 GP register.

In this patch, We bind M4 image with u-boot.bin by allocating a section for m4 image.
So the whole image (included M4 image) will be loaded by A7 ROM into DDR. Then
when u-boot is up, it will try to load M4 image into TCML and boot it there.

Since M4 image will not be relocated in u-boot codes, we must load it during
board_f. Current implementation put it in arch_cpu_init to get M4 booted
as quick as possible.

We requires the M4 image with IVT head and padding embedded, not a RAW binary. The
image should be same as what is used for M4 QSPI boot in dual boot mode.

Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit 04163dbd4f6190f310fff17b53b4bc7b8370ba89)

6 files changed, 75 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/mx7ulp/Kconfig b/arch/arm/cpu/armv7/mx7ulp/Kconfig
index 1bdc85a..a1db6c4 100644
--- a/arch/arm/cpu/armv7/mx7ulp/Kconfig
+++ b/arch/arm/cpu/armv7/mx7ulp/Kconfig
@@ -3,6 +3,12 @@ if ARCH_MX7ULP
 config SYS_SOC
 	default "mx7ulp"
 
+config IMX_M4_BIND
+	bool "Bind ULP M4 image to final u-boot"
+	help
+	  Select this to bind a ULP M4 image to final u-boot image
+	  User needs put the M4 image ulp_m4.bin under u-boot directory
+
 choice
 	prompt "MX7ULP board select"
 	optional
diff --git a/arch/arm/cpu/armv7/mx7ulp/Makefile b/arch/arm/cpu/armv7/mx7ulp/Makefile
index 0248ea8..2a55b97 100644
--- a/arch/arm/cpu/armv7/mx7ulp/Makefile
+++ b/arch/arm/cpu/armv7/mx7ulp/Makefile
@@ -6,3 +6,4 @@
 #
 
 obj-y	:= soc.o clock.o iomux.o pcc.o scg.o
+obj-$(CONFIG_IMX_M4_BIND) += piggy_m4.o
diff --git a/arch/arm/cpu/armv7/mx7ulp/piggy_m4.S b/arch/arm/cpu/armv7/mx7ulp/piggy_m4.S
new file mode 100644
index 0000000..b33e842
--- /dev/null
+++ b/arch/arm/cpu/armv7/mx7ulp/piggy_m4.S
@@ -0,0 +1,2 @@
+	.section .firmware_image,#alloc
+	.incbin	"ulp_m4.bin"
diff --git a/arch/arm/cpu/armv7/mx7ulp/soc.c b/arch/arm/cpu/armv7/mx7ulp/soc.c
index 4fd4c3a..d0f4897 100644
--- a/arch/arm/cpu/armv7/mx7ulp/soc.c
+++ b/arch/arm/cpu/armv7/mx7ulp/soc.c
@@ -6,6 +6,7 @@
 #include <asm/io.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
+#include <asm/sections.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/imx-common/hab.h>
 
@@ -49,8 +50,46 @@ enum bt_mode get_boot_mode(void)
 	return LOW_POWER_BOOT;
 }
 
+#ifdef CONFIG_IMX_M4_BIND
+char __firmware_image_start[0] __attribute__((section(".__firmware_image_start")));
+char __firmware_image_end[0] __attribute__((section(".__firmware_image_end")));
+
+int mcore_early_load_and_boot(void)
+{
+	u32 *src_addr = (u32 *)&__firmware_image_start;
+	u32 *dest_addr = (u32 *)TCML_BASE; /*TCML*/
+	u32 image_size = SZ_128K + SZ_64K; /* 192 KB*/
+	u32 pc = 0, tag = 0;
+
+	memcpy(dest_addr, src_addr, image_size);
+
+	/* Set GP register to tell the M4 rom the image entry */
+	/* We assume the M4 image has IVT head and padding which
+	 * should be same as the one programmed into QSPI flash
+	 */
+	tag = *(dest_addr + 1024);
+	if (tag != 0x402000d1)
+		return -1;
+
+	pc = *(dest_addr + 1025);
+
+	writel(pc, SIM0_RBASE + 0x70); /*GP7*/
+
+	return 0;
+}
+#endif
+
 int arch_cpu_init(void)
 {
+#ifdef CONFIG_IMX_M4_BIND
+	int ret;
+	if (get_boot_mode() == SINGLE_BOOT) {
+		ret = mcore_early_load_and_boot();
+		if (ret)
+			puts("Invalid M4 image, boot failed\n");
+	}
+#endif
+
 	return 0;
 }
 
@@ -149,6 +188,10 @@ int print_cpuinfo(void)
 	case SINGLE_BOOT:
 	default:
 		printf("Single boot\n");
+#ifdef CONFIG_IMX_M4_BIND
+		if (readl(SIM0_RBASE + 0x70))
+			printf("M4 start at 0x%x\n", readl(SIM0_RBASE + 0x70));
+#endif
 		break;
 	}
 
diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
index 37d4c60..38defae 100644
--- a/arch/arm/cpu/u-boot.lds
+++ b/arch/arm/cpu/u-boot.lds
@@ -172,6 +172,22 @@ SECTIONS
 		*(.__image_copy_end)
 	}
 
+#ifdef CONFIG_IMX_M4_BIND
+	.firmware_image_start : {
+                *(.__firmware_image_start)
+        }
+
+	.firmware_image : {
+		KEEP(*(.firmware_image))
+        }
+
+	.firmware_image_end : {
+                *(.__firmware_image_end)
+        }
+
+	. = ALIGN(4);
+#endif
+
 	.rel_dyn_start :
 	{
 		*(.__rel_dyn_start)
diff --git a/arch/arm/imx-common/Kconfig b/arch/arm/imx-common/Kconfig
index c75a38e..c2d2f40 100644
--- a/arch/arm/imx-common/Kconfig
+++ b/arch/arm/imx-common/Kconfig
@@ -47,3 +47,10 @@ config DBG_MONITOR
 	  This option enables the debug monitor which prints out last 
 	  failed AXI access info when system reboot is caused by AXI 
 	  access failure.
+
+config IMX_M4_BIND
+	bool "Bind ULP M4 image to final u-boot"
+	depends on ARCH_MX7ULP
+	help
+	  Select this to bind a ULP M4 image to final u-boot image
+	  User needs put the M4 image ulp_m4.bin under u-boot directory