Re: [PATCH 2/2] ARM: imx: Pick correct eMMC boot partition from ROM log

Hello Marek,

Am Donnerstag, den 01.07.2021, 01:08 +0200 schrieb Marek Vasut:

In case the iMX8M boot from eMMC boot partition and the primary image is corrupted, the BootROM is capable of starting a secondary image in the other eMMC boot partition as a fallback.

I would like to ask a more general question. As I could not find information about that. What are the criteria for the BootROM to consider a image as corrupted? I remember on other platforms with NAND where it was a erased page or too many bitflips. What is it here with eMMC?

Thanks, Teresa

However, the BootROM leaves the eMMC BOOT_PARTITION_ENABLE setting as it was, i.e. pointing to the boot partition containing the corrupted image, and the BootROM does not provide any indication that this sort of fallback occured.

According to AN12853 i.MX ROMs Log Events, Rev. 0, May 2020, it is possible to determine whether fallback event occurred by parsing the ROM event log. In case ROM event ID 0x51 is present, fallback event did occur.

This patch implements ROM event log parsing and search for event ID 0x51 for all iMX8M SoCs, and based on that corrects the eMMC boot partition selection. This way, the SPL loads the remaining boot components from the same eMMC boot partition from which it was started, even in case of the fallback.

Signed-off-by: Marek Vasut marex@denx.de Cc: Faiz Abbas faiz_abbas@ti.com Cc: Harald Seiler hws@denx.de Cc: Lokesh Vutla lokeshvutla@ti.com Cc: Simon Glass sjg@chromium.org Cc: Fabio Estevam festevam@gmail.com Cc: Peng Fan peng.fan@nxp.com Cc: Stefano Babic sbabic@denx.de Cc: Ye Li ye.li@nxp.com

---

arch/arm/mach-imx/imx8m/soc.c | 61 +++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)

diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach- imx/imx8m/soc.c index 0c44022a6dc..92a71b6ba29 100644 --- a/arch/arm/mach-imx/imx8m/soc.c +++ b/arch/arm/mach-imx/imx8m/soc.c @@ -571,6 +571,67 @@ enum boot_device get_boot_device(void) } #endif

+#if defined(CONFIG_IMX8M) +#include <spl.h> +int spl_mmc_emmc_boot_partition(struct mmc *mmc) +{

• u32 *rom_log_addr = (u32 *)0x9e0;
• u32 *rom_log;
• u8 event_id;
• int i, part;
• part = default_spl_mmc_emmc_boot_partition(mmc);
• /* If the ROM event log pointer is not valid. */
• if (*rom_log_addr < 0x900000 || *rom_log_addr >= 0xb00000 ||

•    *rom_log_addr & 0x3)
  

• return part;
  

• /* 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 */
  

• 	break;
  

• /* Log entries with 1 parameter, skip 1 */
  

• case 0x80: /* Start to perform the device
  

initialization */

• case 0x81: /* The boot device initialization completes
  

*/

• 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:
  

• 	/*
  

• 	 * Swap the eMMC boot partitions in case there
  

was a

• 	 * fallback event (i.e. primary image was
  

corrupted

• 	 * and that corruption was recognized by the
  

BootROM),

• 	 * so the SPL loads the rest of the U-Boot from
  

the

• 	 * correct eMMC boot partition, since the
  

BootROM

• 	 * leaves the boot partition set to the
  

corrupted one.

• 	 */
  

• 	if (part == 1)
  

• 		part = 2;
  

• 	else if (part == 2)
  

• 		part = 1;
  

• 	continue;
  

• default:
  

• 	continue;
  

• }
  

• }
• return part;

+} +#endif

bool is_usb_boot(void) { return get_boot_device() == USB_BOOT;