On Tue, Oct 22, 2024 at 01:05:21PM -0700, Raymond Mao wrote:
Motivations for changes: Current SMBIOS library and command-line tool is not fully matching with the requirements:
- Missing support for other mandatory types (#7, #9, #16, #17, #19).
- Only a few platforms support SMBIOS node from the device tree.
- Values of some fields are hardcoded in the library other than fetching from the device hardware.
- Embedded data with dynamic length is not supported (E.g. Contained Object Handles in Type #2 and Contained Elements in Type #3)
Changes:
- Refactor the SMBIOS library and command-line tool to better align with the SMBIOS spec.
- Create an arch-specific driver for all aarch64-based platforms to fetch SMBIOS private data from the device hardware (processor and cache).
- Create a sysinfo driver to poppulate platform SMBIOS private data.
- Add generic SMBIOS DTS file for arm64 platforms for those common strings and values which cannot be retrieved from the system registers. Vendors can create their own SMBIOS node using this as an example. For those boards without SMBIOS nodes, this DTS file can be included to have a generic SMBIOS information of the system.
- Add support for Type #7 (Cache Information) and link its handles to Type #4.
Once this patch is acceptted, subsequent patch sets will add other missing types (#9, #16, #17, #19).
Tests: To test this with QEMU arm64, please follow the guide on dt_qemu.rst to get a merged DT to run with.
qemu-system-arm -machine virt -machine dumpdtb=qemu.dtb cat <(dtc -I dtb qemu.dtb) <(dtc -I dtb ./dts/dt.dtb | grep -v /dts-v1/) \ | dtc - -o merged.dtb qemu-system-arm -machine virt -nographic -bios u-boot.bin -dtb merged.dtbKnown issues: It hits the image size limitation on R-CAR board(rcar3_salvator-x).
u-boot.img exceeds file size limit: limit: 0x100000 bytes actual: 0x10049d bytes excess: 0x49d bytesThis board needs a clean-up to reserve spaces for the changes as SMBIOS is a fundamental feature.
Below is the breakdown of the size-growth of the related functions: function old new delta static.smbios_write_type4 252 1052 +800 static.smbios_write_type7 - 764 +764 static.smbios_write_type3 188 488 +300 smbios_get_val_si - 128 +128 static.smbios_write_type2 316 376 +60 sysinfo_get_data - 56 +56 static.smbios_write_type1 380 396 +16 smbios_write_funcs 112 128 +16 ofnode_read_u32 - 12 +12 sysinfo_rcar_ops 40 48 +8 install_smbios_table 468 472 +4
Right, so here's the problem I see right now. About 70% of all U-Boot platforms enable GENERATE_SMBIOS_TABLE and so "smbios: Refactor smbios library" causes a growth of around 1.5 kilobytes. That's a problem. There is a place where we're going to generate as full and complete a table as we can, and a place where we just want maybe the basics. We need to re-factor things first so that the platforms which aren't doing detailed tables do not grow and perhaps even shrink because we can pull existing code out.