On Fri, Nov 03, 2023 at 12:14:46PM -0600, Simon Glass wrote: > Hi Heinrich, > > On Fri, 3 Nov 2023 at 11:52, Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > > > > > > > Am 3. November 2023 19:12:40 OEZ schrieb Simon Glass <s...@chromium.org>: > > >Hi, > > > > > >On Sat, 28 Oct 2023 at 12:41, Simon Glass <s...@chromium.org> wrote: > > >> > > >> [unfortunately I am not receiving email from the list at present] > > >> > > >> Hi Heinrich, > > >> > > >> On Wed, 25 Oct 2023 at 21:39, Heinrich Schuchardt <xypron.g...@gmx.de> > > >> wrote: > > >> > > > >> > On 10/25/23 04:49, Simon Glass wrote: > > >> > > Hi Heinrich, > > >> > > > > >> > > On Tue, 24 Oct 2023 at 18:22, Heinrich Schuchardt > > >> > > <xypron.g...@gmx.de> wrote: > > >> > >> > > >> > >> > > >> > >> > > >> > >> Am 25. Oktober 2023 01:31:19 MESZ schrieb Simon Glass > > >> > >> <s...@chromium.org>: > > >> > >>> U-Boot typically sets up its malloc() pool near the top of memory. > > >> > >>> On > > >> > >>> ARM64 systems this can result in an SMBIOS table above 4GB which is > > >> > >>> not supported by SMBIOSv2. > > >> > >>> > > >> > >>> Work around this problem by providing a new option to choose an > > >> > >>> address > > >> > >>> below 4GB (but as high as possible), if needed. > > >> > >> > > >> > >> You must not overwrite memory controlled by the EFI subsystem > > >> > >> without calling its allocator. We should provide SMBIOS 3. SMBIOS > > >> > >> 2 is only a fallback for outdated tools. > > >> > > > > >> > > That is not my intention and I don't believe this code does that. EFI > > >> > > is not running at this point, is it? > > >> > > > >> > The function install_smbios_table() only exists if CONFIG_EFI_LOADER=y. > > >> > > >> That is because ARM devices don't normally need it, right? Anyway, > > >> that option isn't related to this patch. If ARM devices started using > > >> SMBIOS and had another way to pass it to Linux (other than EFI) then > > >> we would want to install it. > > >> > > >> > > > >> > We have: > > >> > EVENT_SPY_SIMPLE(EVT_LAST_STAGE_INIT, install_smbios_table); > > >> > This is invoked after efi_memory_init(). > > >> > > > >> > The EFI specification requires that the memory area occupied by the > > >> > SMBIOS table uses one of a specific set of memory types where > > >> > EfiRuntimeServicesData is recommended. So you must call > > >> > > > >> > u64 addr = UINT_MAX; > > >> > ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, > > >> > EFI_RUNTIME_SERVICES_DATA, efi_size_in_pages(size), *addr); > > >> > > > >> > to allocate the memory. If the return code is not EFI_SUCCESS, no > > >> > memory > > >> > below 4 GiB is available. > > >> > > >> The root problem here is that x86 and ARM used to work differently. > > >> When the ARM SMBIOS stuff was done, it worked by writing the SMBIOS > > >> table as part of the 'bootefi' command. On x86, the tables were > > >> written on startup, so you can examine them within U-Boot. Clearly the > > >> x86 approach is correct. For one thing, a previous-stage bootloader > > >> may set up the tables, so it simply isn't valid to write them in that > > >> case. So we need to separate writing the tables from telling EFI about > > >> them. > > >> > > >> So I have fixed that, so ARM now writes the tables at the start. But > > >> using an EFI allocation function is clearly not right. This is generic > > >> code, nothing to do with EFI, really. In fact, the SMBIOS writing > > >> should move out of efi_loader. The install_smbios_table() function > > >> should be somewhere in lib, i suppose, with just efi_smbios_register() > > >> sitting in lib/efi_loader > > >> > > >> Also, why is efi_memory_init() called early in init? Is there anything > > >> that needs that in the init sequence? Could we move it to the end, or > > >> perhaps skip it completely until the 'bootefi' command is used? > > >> > > >> Another point I should make is that it should be fine for U-Boot to > > >> put something in memory and then call efi_add_memory_map() to tell EFI > > >> about it. What problems does that cause? It isn't as if EFI allocates > > >> things in the 'conventional' memory (is that the name for memory below > > >> 4GB?) This is how efi_acpi_register() works. > > >> > > >> (Aside: it is bizarre to me that CONFIG_EFI_LOADER appears in > > >> drivers/video/rockchip_rk_vop.c and other such files) > > >> > > >> > > > >> > > > > >> > > The bit I am confused about is that we don't support SMBIOS3 in > > >> > > U-Boot. I am trying to fix an introduced bug... > > >> > > > >> > I would not know why we should not use SMBIOS 3. > > >> > > >> Neither do I. Perhaps there are compatibility concerns? If it is OK to > > >> do that then we could go back to my previous series [1]. What do you > > >> think? > > > > > >Tom responded but I missed it. In part it says: > > > > > >"So, can we please start by just doing the minimal changes to get the > > >SMBIOS table done correctly for memory above 4G, via EFI, and then start > > >the next steps?" > > > > > >I am OK to do an EFI hack for ARM so long as we agree that after the > > >release we will revert it and generate the table using generic memory > > >allocation, not dependent on EFI. Does that sound reasonable? > > > > > >I don't seem to have received any response from Heinrich to the > > >various points I made above. I cannot see any response on patchwork > > >either. > > > > > >Regards, > > >Simon > > > > All memory below the stack is controlled by the EFI subsystem. I notified > > you of the function you need to call. I can't see what information you are > > lacking. > > That is fine when EFI is used, but what about when it is not? That is > the piece I don't yet understand.
We also don't have the use case for when EFI is not used defined and understood, so it can wait until then? -- Tom
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