summaryrefslogtreecommitdiff
path: root/arch/loongarch/kernel/env.c
AgeCommit message (Collapse)AuthorFilesLines
2024-01-17LoongArch: Parsing CPU-related information from DTSBinbin Zhou1-1/+33
Generally, we can get cpu-related information, such as model name, from /proc/cpuinfo. For FDT-based systems, we need to parse the relevant information from DTS. BTW, set loongson_sysconf.cores_per_package to num_processors if SMBIOS doesn't provide a valid number (usually FDT-based systems). Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: Add FDT booting support from efi system tableBinbin Zhou1-0/+2
Since commit 40cd01a9c324("efi/loongarch: libstub: remove dependency on flattened DT"), we can parse the FDT from efi system table. And now, LoongArch is coming to support booting with FDT, so we add the relevant booting support as well as parameter parsing. Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-09-27efi/loongarch: libstub: remove dependency on flattened DTArd Biesheuvel1-9/+4
LoongArch does not use FDT or DT natively [yet], and the only reason it currently uses it is so that it can reuse the existing EFI stub code. Overloading the DT with data passed between the EFI stub and the core kernel has been a source of problems: there is the overlap between information provided by EFI which DT can also provide (initrd base/size, command line, memory descriptions), requiring us to reason about which is which and what to prioritize. It has also resulted in ABI leaks, i.e., internal ABI being promoted to external ABI inadvertently because the bootloader can set the EFI stub's DT properties as well (e.g., "kaslr-seed"). This has become especially problematic with boot environments that want to pretend that EFI boot is being done (to access ACPI and SMBIOS tables, for instance) but have no ability to execute the EFI stub, and so the environment that the EFI stub creates is emulated [poorly, in some cases]. Another downside of treating DT like this is that the DT binary that the kernel receives is different from the one created by the firmware, which is undesirable in the context of secure and measured boot. Given that LoongArch support in Linux is brand new, we can avoid these pitfalls, and treat the DT strictly as a hardware description, and use a separate handover method between the EFI stub and the kernel. Now that initrd loading and passing the EFI memory map have been refactored into pure EFI routines that use EFI configuration tables, the only thing we need to pass directly is the kernel command line (even if we could pass this via a config table as well, it is used extremely early, so passing it directly is preferred in this case.) Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Remove unused variablesBibo Mao1-20/+0
There are some variables never used or referenced, this patch removes these varaibles and make the code cleaner. Reviewed-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03LoongArch: Add boot and setup routinesHuacai Chen1-0/+101
Add basic boot, setup and reset routines for LoongArch. Now, LoongArch machines use UEFI-based firmware. The firmware passes configuration information to the kernel via ACPI and DMI/SMBIOS. Currently an existing interface between the kernel and the bootloader is implemented. Kernel gets 2 values from the bootloader, passed in registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and non-UEFI firmware, while a1 is a pointer to an FDT with systable, memmap, cmdline and initrd information. The standard UEFI boot protocol (EFISTUB) will be added later. Cc: linux-efi@vger.kernel.org Cc: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Co-developed-by: Yun Liu <liuyun@loongson.cn> Signed-off-by: Yun Liu <liuyun@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>