different PM_RSTS register content when doing an u-boot reset between v20250430 and v20250915?

Start with the u-boot reset command and the dtparam=watchdog=on setting in config.txt, then compare the PM_RSTS, partition selection, and watchdog behavior shown for versions v20250430 and v20250915. Check how autoboot.txt is interpreted during reset; done means identifying the version change and ensuring reset selects the intended partition without the unwanted partition 32 attempt.

Hi,

when applying a reset command from within u-boot (on a CM4), the content of the PM_RSTS has different values between these 2 versions after the reset. This leads to different boot partitions used by the EEPROM-bootloader:

Version 20250915 after an u-boot reset command:

0.18 RPi: BOOTSYS release VERSION:75c1e570 DATE: 2025/02/11 TIME: 17:00:13
  0.22 BOOTMODE: 0x06 partition 32 build-ts BUILD_TIMESTAMP=1739293213 serial 73d45949 boardrev d03141 stc 522662
  0.32 PM_RSTS 00000420
  0.34 POWER_OFF_ON_HALT: 1 WAIT_FOR_POWER_BUTTON 0 power-on-reset 0
  0.50 part 00000020 reset_info 00000000
  0.51 uSD voltage 3.3V
  0.77 Initialising SDRAM rank 2 total-size: 64 Gbit 3200 (0x14 0x00)
  0.80 DDR 3200 1 0 64 152 BL:3
  2.80 OTP boardrev d03141 bootrom 48b0 48b0
  2.82 Customer key hash 0000000000000000000000000000000000000000000000000000000000000000
  2.89 VC-JTAG unlocked


  2.67 RPi: BOOTLOADER release VERSION:75c1e570 DATE: 2025/02/11 TIME: 17:00:13
  2.72 BOOTMODE: 0x06 partition 32 build-ts BUILD_TIMESTAMP=1739293213 serial 73d45949 boardrev d03141 stc 2472066
  2.07 Boot mode: SD (01) order f
  2.22 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.32 SD HOST: 200000000 CTL0: 0x00800f00 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.41 EMMC
  2.41 SD retry 1 oc 0
  2.66 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.77 OCR c0ff8080 [0]
CID: 00150100384754463452064e135fa46a
  2.97 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 25000000 Hz actual: 25000000 HZ div: 8 (4) status: 0x1fff0000 delay: 4
  2.07 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 50000000 Hz actual: 50000000 HZ div: 4 (2) status: 0x1fff0000 delay: 2
  2.16 MBR: 0x00000800,  102400 type: 0x0c
  2.19 MBR: 0x0001a000,  102400 type: 0x0c
  2.22 MBR: 0x00033000,  102400 type: 0x0c
  2.26 MBR: 0x0004c7fe,14948354 type: 0x0f
  2.30 Trying partition: 0
  2.33 type: 16 lba: 2048 'mkfs.fat' '  V       ^ ' clusters 25541 (4)
  2.39 rsc 4 fat-sectors 100 root dir cluster 1 sectors 32 entries 512
  2.45 FAT16 clusters 25541
  2.49 Read autoboot.txt bytes       23 hnd 0x3
  2.52 Select partition rsts 32 C(boot_partition) 3 EEPROM config 0 result 32
  2.59 Trying partition: 32
  2.61 EBR: 0x0004c7fe 0x00000002, 2048000 0x001f4782, 9420928 signature: aa55
  2.68 EBR: 0x00240f80 0x00000080, 9420800 0x00af0f82, 1024128 signature: aa55
  2.75 EBR: 0x00b3d780 0x00000080, 1024000 0x00beb782, 2048128 signature: aa55
  2.82 EBR: 0x00c37f80 0x00000080, 2048000 0x00ddff82,  399488 signature: aa55
  2.89 EBR: 0x00e2c780 0x00000080,  399360 0x00000000,       0 signature: aa55
  2.96 Failed to open partition 32

Version 20253004 after an u-boot reset command (starts correct partition stated in autoboot.txt):

0.20 RPi: BOOTSYS release VERSION:75c1e570 DATE: 2025/02/11 TIME: 17:00:13
  0.24 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1739293213 serial 73d45949 boardrev d03141 stc 524132
  0.34 PM_RSTS 00000020
  0.36 POWER_OFF_ON_HALT: 1 WAIT_FOR_POWER_BUTTON 0 power-on-reset 0
  0.53 part 00000000 reset_info 00000000
  0.54 uSD voltage 3.3V
  0.80 Initialising SDRAM rank 2 total-size: 64 Gbit 3200 (0x14 0x00)
  0.83 DDR 3200 1 0 64 152 BL:3
  2.84 OTP boardrev d03141 bootrom 48b0 48b0
  2.86 Customer key hash 0000000000000000000000000000000000000000000000000000000000000000
  2.93 VC-JTAG unlocked


  2.72 RPi: BOOTLOADER release VERSION:75c1e570 DATE: 2025/02/11 TIME: 17:00:13
  2.76 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1739293213 serial 73d45949 boardrev d03141 stc 2476492
  2.11 Boot mode: SD (01) order f
  2.26 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.37 SD HOST: 200000000 CTL0: 0x00800f00 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.46 EMMC
  2.46 SD retry 1 oc 0
  2.70 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276
  2.82 OCR c0ff8080 [0]
CID: 00150100384754463452064e135fa46a
  2.01 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 25000000 Hz actual: 25000000 HZ div: 8 (4) status: 0x1fff0000 delay: 4
  2.12 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 50000000 Hz actual: 50000000 HZ div: 4 (2) status: 0x1fff0000 delay: 2
  2.20 MBR: 0x00000800,  102400 type: 0x0c
  2.23 MBR: 0x0001a000,  102400 type: 0x0c
  2.27 MBR: 0x00033000,  102400 type: 0x0c
  2.31 MBR: 0x0004c7fe,14948354 type: 0x0f
  2.34 Trying partition: 0
  2.37 type: 16 lba: 2048 'mkfs.fat' '  V       ^ ' clusters 25541 (4)
  2.43 rsc 4 fat-sectors 100 root dir cluster 1 sectors 32 entries 512
  2.50 FAT16 clusters 25541
  2.54 Read autoboot.txt bytes       23 hnd 0x4
  2.56 Select partition rsts 0 C(boot_partition) 2 EEPROM config 1 result 2
  2.63 Trying partition: 2
  2.65 type: 12 lba: 106496 'mkfs.fat' '  V       ^ ' clusters 1133 (4)
  2.72 rsc 1 fat-sectors 4 root dir cluster 1 sectors 32 entries 512
  2.78 FAT12 clusters 1133
  2.80 secure-boot
  2.82 Loading boot.img ...
  2.85 boot.sig

Also in the old version u-boot is watchdog resetted after some seconds and on the new version it is not. What exactly has changed here? It is really a problem that it trys to start partition 32.

in config.txt I have "dtparam=watchdog=on"