[REGRESSION] Out of memory error: unable to boot on imx8mp/imx8mm

[João Paulo Gonçalves]

Hello,

U-Boot is not able too boot on imx8mm and imx8mp and gives out of memory
errors:

U-Boot SPL 2025.01-rc4-00041-g50334151c020 (Dec 15 2024 - 14:02:46 +0000)
Training FAILED
DDR configured as single rank
WDT:   Started watchdog at 30280000 with servicing every 1000ms (60s timeout)
SEC0:  RNG instantiated
Normal Boot
Trying to boot from BOOTROM
Boot Stage: Primary boot
Find img info 0x4802f000, size 1116
Need continue download 1024
NOTICE:  Do not release JR0 to NS as it can be used by HAB
NOTICE:  BL31: v2.10.0	(release):android-14.0.0_2.2.0-rc2-0-g7c64d4e86-dirty
NOTICE:  BL31: Built : 10:35:32, Aug 29 2024
U-Boot 2025.01-rc4-00041-g50334151c020 (Dec 15 2024 - 14:02:46 +0000)
CPU:   Freescale i.MX8MP[8] rev1.1 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 24C
Reset cause: POR
DRAM:  4 GiB
Core:  183 devices, 31 uclasses, devicetree: separate
WDT:   Started watchdog at 30280000 with servicing every 1000ms (60s timeout)
out of memory
ERROR: Out of memory
MMC:   FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... out of memory
out of memory
Adding partition for mmc at 30b60000.blk:1 failed
*** Warning - No block device, using default environment
out of memory
out of memory
Adding partition for mmc at 30b60000.blk:1 failed

The regression was introduced with commit 1a48b0be93d4 ('lmb: prohibit
allocations above ram_top even from same bank'). Reverting it, allows U-Boot to
boot again. The issue seems to occur on modules with >=4Gb of RAM.

Do you have any idea what might be causing the issue? On our boards, the first
error occurs in efi_init_early() and then in initr_mmc(), and it happens during
memory allocation using lmb.

Best Regards,
João Paulo Gonçalves