I think my MacBook with soldered RAM has a RAM issue.  With memtest86+, I figured out which BadRAM pattern I have, but I cannot interpret the result correctly.  How should I read the range to set up the right exclusion in GRUB? Here are my memtest results:

BadRAM Patterns
---------------
badram=0x0000000058cb4000,0xfffffffffffffc00,
       0x0000000058cb4400,0xfffffffffffffc00,
       0x0000000058cb4800,0xfffffffffffffc00,
       0x0000000058cb4c00,0xfffffffffffffc00,
       0x0000000058cb5000,0xfffffffffffff800,
       0x0000000058cb5800,0xfffffffffffff800,
       0x0000000058cb6000,0xfffffffffffff800,
       0x0000000058cb6800,0xfffffffffffff800,
       0x0000000058cb7000,0xfffffffffffff800,
       0x0000000058cb7800,0xfffffffffffff800

    .] Would memmap=64K$0x58cb0000 be correct?

My Linux machine is having issues with faulty RAM. I ran PCMemTest-64, and I determined the following patterns: Now, I have stock Ubuntu which doesn't seem to have the BadRAM patch, and I'm a bit nervous about compiling Linux from scratch. So I'm wondering if there is an easy way to disable these fault RAM addresses using existing tools in GRUB and Linux, for example using the memmap kernel parameter. I'm happy to lose a bit of RAM other than the faulty addresses (in the order of kilobytes and not gigabytes ideally) to take this shortcut. Some versions: * Linux 5.19.0-32 * Grub 2.06 * Ubuntu 22.04 What should I do?

Recently has been released version 6 of Memtest86+ which finally introduce UEFI support. Now, I use systemd-boot as boot manager, so I'd like to launch memtest86+ directly at boot. I set up a configuration file /boot/loader/entries/memtest.conf as described here ****:

title     Memory Tester (memtest86+)
efi       /memtest86+/memtest.efi

With no luck! It results in a blank screen. **Help me: What I do wrong?** I am on Arch Linux w/ memtest86+-efi **** 6.00-2 **UPDATE1:** reported the issue in Arch Linux bug tracker **** --- **** https://wiki.archlinux.org/title/Systemd-boot#EFI_Shells_or_other_EFI_applications **** https://archlinux.org/packages/extra/any/memtest86+-efi/ **** https://bugs.archlinux.org/task/76390

I would like to use something like memtest86 but for VRAM. I have some artifacts on the screen some times and I'm trying to rule out possibilities.