BadRAM Range: cannot set up the right range

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?