Re: port-amd64/60405: UEFI boot hangs with blank screen

The following reply was made to PR port-amd64/60405; it has been noted by GNATS.

From: RVP <[email protected]>
To: [email protected]
Cc: 
Subject: Re: port-amd64/60405: UEFI boot hangs with blank screen
Date: Sun, 5 Jul 2026 22:29:52 +0000 (UTC)

 On Sun, 5 Jul 2026, Martin Husemann via gnats wrote:
 
 > > memmap compact
 > Type                    Start             End               Attributes
 > ----------------------  ----------------  ----------------  ----------------
 > Conventional Memory     0000000000000000  000000000009efff  000000000000000f
 > Runtime Services Data   000000000009f000  000000000009ffff  800000000000000f
 > Conventional Memory     0000000000100000  00000000deb89fff  000000000000000f
 > [...]
 > So I have three areas "Conventional Memory", the kernel would fit into
 > two of them, but not the middle one starting at 00000000df402000
 >
 
 Yes, that looks OK. Can you show the detailed map (`memmap`) as well? Just the
 1st page alone should be sufficient.
 
 Also, are there any errors logged by apei(4) in CSM mode after the system
 reboots from a failed UEFI boot?
 
 I see something like this in dmesg after the system reboots if I `reloc` the
 kernel to somewhere the system doesn't like:
 
 ```
 [   1.0399465] apei0 at acpi0: ACPI Platform Error Interface
 [   1.0399465] apei0: BERT: OemId <INTEL ,EDK2    ,00000001> AslId <INTL,00000001>
 [   1.0399465] apei0: BERT: 0xe7c bytes at 0x3f919018
 [   1.0399465] apei0: boot error record reported hardware error: severity=fatal nentries=1 status=0x15<UE,MULTI_UE,GEDE_COUNT=0x1>
 [   1.0399465] apei0: boot error record entry 0: SectionType={0x81212a96,0x09ed,0x4996,{0x94,71,0x8d,0x72,0x9c,0x8e,0x69,0xed}}
 [   1.0399465] apei0: boot error record entry 0: ErrorSeverity=1 (fatal)
 [   1.0399465] apei0: boot error record entry 0: Revision=0x300
 [   1.0399465] apei0: boot error record entry 0: ValidationBits=0
 [   1.0399465] apei0: boot error record entry 0: Flags=0
 [   1.0399465] apei0: boot error record entry 0: ErrorDataLength=0x3616
 [   1.0399465] apei0: boot error record: [unknown type]
 [   1.0399465] apei0: autoconfiguration error: BERT: fatal pre-boot error recorded
 ```
 
 -RVP