Detect physical RAM from SMBIOS?

[MatejHorvat]

On this computer with 6 GB (6144 MB) of RAM, hrev54154+31 says it only has 5741 MB with 1 MB inaccessible. I have updated the BIOS to the latest version and this doesn't fix it. However, FreeBSD detects and uses all 6 GB.

[waddlesplash]

This is almost certainly because of hardware-reserved memory that we are not adding to the "inaccessible" range. What does FreeBSD say about that?

[MatejHorvat]

Yes, at least 384 MB seems to be reserved for the GPU. FreeBSD's dmesg says:

real memory  = 6442450944 (6144 MB)
avail memory = 5754912768 (5488 MB)
<...>
[drm] Detected VRAM RAM=384M, BAR=256M
[drm] RAM width 32bits DDR
[TTM] Zone  kernel: Available graphics memory: 2922186 kiB
[TTM] Zone   dma32: Available graphics memory: 2097152 kiB
[TTM] Initializing pool allocator
[drm] radeon: 384M of VRAM memory ready
[drm] radeon: 1024M of GTT memory ready.

Interestingly, it reports less usable RAM than Haiku.

[waddlesplash]

​https://review.haiku-os.org/c/haiku/+/2809

[waddlesplash]

That change was supplanted by hrev54265, see if that changes anything.

However, it looks like FreeBSD's "real memory" section comes from the SMBIOS information, which we do not parse. Since Haiku is seeing as much (or actually more) memory as usable than FreeBSD is, this is just an enhancement at this point.

[MatejHorvat]

In hrev54265, the same amount is reported.