[PATCH 2/2] arch: arm: imx: detect secondary boot

[Fabian Pfitzner <f.pfitzner@pengutronix.de>]

Integrate support to detect secondary boot on imx machines.
Copy the logic for detection from the uboot-imx project[1].

The information will be stored in the `bootsource_instance_index`
variable.

[1] https://github.com/nxp-imx/uboot-imx/blob/99518e6b6f20cb6a2bf19115e355db9f58100af8/arch/arm/mach-imx/imx8m/soc.c#L792

Signed-off-by: Fabian Pfitzner <f.pfitzner@pengutronix.de>
---
 arch/arm/mach-imx/boot.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/arch/arm/mach-imx/boot.c b/arch/arm/mach-imx/boot.c
index 3fea22d05f3bfdf2fe9caa6767e1c7c5ea3ced00..a35a1acc2e71231236d3dd5008523f6c66912000 100644
--- a/arch/arm/mach-imx/boot.c
+++ b/arch/arm/mach-imx/boot.c
@@ -26,6 +26,8 @@
 
 #include <soc/fsl/fsl_udc.h>
 
+int imx8m_detect_secondary_image_boot(void);
+
 static void
 imx_boot_save_loc(void (*get_boot_source)(enum bootsource *, int *))
 {
@@ -35,6 +37,10 @@ imx_boot_save_loc(void (*get_boot_source)(enum bootsource *, int *))
 	get_boot_source(&src, &instance);
 
 	bootsource_set(src, instance);
+
+	int index = imx8m_detect_secondary_image_boot();
+
+	bootsource_set_instance_index(index);
 }
 
 
@@ -756,3 +762,49 @@ void imx8mn_get_boot_source(enum bootsource *src, int *instance)
 
 void imx8mn_boot_save_loc(void)
 	__alias(imx8mp_boot_save_loc);
+
+int imx8m_detect_secondary_image_boot(void)
+{
+	u32 *rom_log_addr = (u32 *)0x9e0;
+	u32 *rom_log;
+	u8 event_id;
+	int i, boot_secondary = 0;
+
+	/* If the ROM event log pointer is not valid. */
+	if (*rom_log_addr < 0x900000 || *rom_log_addr >= 0xb00000 ||
+	    *rom_log_addr & 0x3)
+		return -EINVAL;
+
+	/* Parse the ROM event ID version 2 log */
+	rom_log = (u32 *)(uintptr_t)(*rom_log_addr);
+	for (i = 0; i < 128; i++) {
+		event_id = rom_log[i] >> 24;
+		switch (event_id) {
+		case 0x00: /* End of list */
+			return boot_secondary;
+		/* Log entries with 1 parameter, skip 1 */
+		case 0x80: /* Start to perform the device initialization */
+		case 0x81: /* The boot device initialization completes */
+		case 0x82: /* Starts to execute boot device driver pre-config */
+		case 0x8f: /* The boot device initialization fails */
+		case 0x90: /* Start to read data from boot device */
+		case 0x91: /* Reading data from boot device completes */
+		case 0x9f: /* Reading data from boot device fails */
+			i += 1;
+			continue;
+		/* Log entries with 2 parameters, skip 2 */
+		case 0xa0: /* Image authentication result */
+		case 0xc0: /* Jump to the boot image soon */
+			i += 2;
+			continue;
+		/* Boot from the secondary boot image */
+		case 0x51:
+			boot_secondary = 1;
+			continue;
+		default:
+			continue;
+		}
+	}
+
+	return boot_secondary;
+}

-- 
2.47.3