| 10 Mar 2025 |
 @elvishjerricco:matrix.org | oh great. The user practically ignored my request for HW info and decided to bisect nixpkgs instead of considering the systemd issue I linked | 18:07:11 |
| @elvishjerricco:matrix.org | guess we'll see them again in a day or two | 18:07:34 |
 raitobezarius | (lol) | 18:08:07 |
| raitobezarius | i think it's a great experience to bisect baremetal HW | 18:08:15 |
| raitobezarius | I totally did not put my little brother to this task for the last 2 weeks | 18:08:28 |
| raitobezarius | they would have a better chance just reverting the systemdp atch | 18:09:05 |
| raitobezarius | now we are talking about bisections, i'm going to post this: http://kernel.org/pub/linux/kernel/people/paulmck/Answers/Heisenbugs/QQAbisection.html | 18:09:18 |
| @elvishjerricco:matrix.org | raitobezarius: Do you know if it would be possible to make qemu emulate an x86_64 system with this sort of issue? | 18:11:43 |
| raitobezarius | well, you know what we did last time right | 18:12:09 |
| raitobezarius | let me check the source code of qemu quickly | 18:12:24 |
| raitobezarius | basically | 18:13:30 |
| raitobezarius | bool x86_cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
Error **errp);
| 18:13:32 |
| raitobezarius | i think this needs to answer "yo bro i have nothing for you below 4GB boundary" | 18:13:41 |
| raitobezarius | then you are going to reproduce it | 18:13:50 |
| raitobezarius | target/i386/cpu.h | 18:14:01 |
| raitobezarius | hmm | 18:14:37 |
| raitobezarius | i think there's easier ways to do it | 18:14:40 |
| raitobezarius | https://www.qemu.org/docs/master/devel/memory.html | 18:14:42 |
| @elvishjerricco:matrix.org | I thought we just tested everything on bare metal asahi machines | 18:15:33 |
| raitobezarius | In reply to @elvishjerricco:matrix.org
I thought we just tested everything on bare metal asahi machines the day where the sd-boot read() was relying on the firmware not being broken | 18:15:51 |
| @elvishjerricco:matrix.org | oh I fixed that by fucking with the OVMF implementation in a cursed way | 18:16:09 |
| @elvishjerricco:matrix.org | which I guess would be another way to do this, huh? | 18:16:16 |
| raitobezarius | memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", machine->ram,
0, x86ms->below_4g_mem_size);
| 18:16:36 |
| raitobezarius | either you patch OVMF | 18:16:40 |
| @elvishjerricco:matrix.org | * oh I tested that by fucking with the OVMF implementation in a cursed way | 18:16:42 |
| raitobezarius | either you patch QEMU | 18:16:43 |
| raitobezarius | just kill these lines | 18:16:57 |
| raitobezarius | ram_below_4g = g_malloc(sizeof(*ram_below_4g));
memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", machine->ram,
0, x86ms->below_4g_mem_size);
memory_region_add_subregion(system_memory, 0, ram_below_4g);
| 18:17:00 |
| raitobezarius | i think that's enough to make RAM below 4GB disappear | 18:17:05 |
| raitobezarius | (pc.c file) | 18:17:13 |
