Hi Yao, On 2026-07-01T11:17:53, Yao Zi <[email protected]> wrote: > LoongArch: Boot Image bits > > Implement loading and booting functions for LoongArch > standard kernel image as per spec. > > LoongArch kernel do expect us to fake a efi systemtable > for passing fdt to kernel, we don't need to implement any > EFI functions for kernel because it won't look into anything > beside devicetree from that table if we tell kernel we are > not efi compatible by setting a0 boot argument to zero. > > Link: https://docs.kernel.org/arch/loongarch/booting.html > Signed-off-by: Jiaxun Yang <[email protected]> > Signed-off-by: Yao Zi <[email protected]> > > arch/loongarch/lib/Makefile | 2 + > arch/loongarch/lib/bootm.c | 163 > ++++++++++++++++++++++++++++++++++++++++++++ > arch/loongarch/lib/image.c | 66 ++++++++++++++++++ > cmd/Kconfig | 2 +- > 4 files changed, 232 insertions(+), 1 deletion(-)
> diff --git a/arch/loongarch/lib/bootm.c b/arch/loongarch/lib/bootm.c > @@ -0,0 +1,163 @@ > +#include <bootstage.h> > +#include <bootm.h> > +#include <command.h> > +#include <dm.h> > +#include <efi.h> > +#include <efi_api.h> > +#include <fdt_support.h> > +#include <hang.h> > +#include <log.h> > +#include <linux/sizes.h> > +#include <memalign.h> > +#include <asm/global_data.h> > +#include <dm/root.h> > +#include <image.h> > +#include <asm/byteorder.h> > +#include <dm/device.h> > +#include <dm/root.h> > +#include <u-boot/zlib.h> dm/root.h is listed twice - please drop the duplicate, and sort the block while you are here. https://docs.u-boot.org/en/latest/develop/codingstyle.html#include-files > diff --git a/arch/loongarch/lib/bootm.c b/arch/loongarch/lib/bootm.c > @@ -0,0 +1,163 @@ > +/* LoongArch do expect a EFI style systab */ > +static int generate_systab(struct bootm_headers *images) > +{ > + const int nr_cfgtab = 1; > + struct bd_info *kbd = images->kbd; > + struct efi_system_table *systab; > + struct efi_configuration_table *cfgtab; > + size_t table_size = sizeof(struct efi_system_table) + > + nr_cfgtab * sizeof(struct efi_configuration_table); > + > + systab = memalign(SZ_64K, table_size); Please add a comment on why 64K alignment is required. > diff --git a/arch/loongarch/lib/bootm.c b/arch/loongarch/lib/bootm.c > @@ -0,0 +1,163 @@ > +static void boot_jump_linux(struct bootm_headers *images, int flag) > +{ > + void (*kernel)(ulong efi_boot, char *argc, void *dtb); > + int fake = (flag & BOOTM_STATE_OS_FAKE_GO); > + > + kernel = (void (*)(ulong efi_boot, char *argc, void *dtb))images->ep; The second argument is the kernel command line, not argc - please rename to cmdline. The third is the fake systab pointer, not a raw dtb; please rename that too. > diff --git a/arch/loongarch/lib/bootm.c b/arch/loongarch/lib/bootm.c > @@ -0,0 +1,163 @@ > + if (!fake) { > + if (CONFIG_IS_ENABLED(OF_LIBFDT) && images->ft_len) > + kernel(0, NULL, (void *)images->kbd->bi_boot_params); > + } Per the LoongArch booting spec, a1 is the kernel command line. Passing NULL means the bootargs env var never reaches the kernel via that path - it will only be seen in /chosen/bootargs So don't you wan to pass images->cmdline_start here? Also, if OF_LIBFDT is disabled or ft_len is zero we drop through without jumping *after* announce_and_cleanup() has torn devices down. Please panic() / hang() in that case rather than silently return. > diff --git a/arch/loongarch/lib/image.c b/arch/loongarch/lib/image.c > @@ -0,0 +1,66 @@ > +struct linux_image_h { > + uint32_t code0; /* Executable code */ > + uint32_t code1; /* Executable code */ > + uint64_t kernel_entry; /* Kernel entry point */ > + uint64_t image_size; /* Effective Image size */ > + uint64_t load_offset; /* load offset */ > + uint64_t res1; /* reserved */ > + uint64_t res2; /* reserved */ > + uint64_t res3; /* reserved */ > + uint32_t magic; /* Magic number */ > + uint32_t pe_header; /* Offset to the PE header */ > +}; Comment tabs after kernel_entry/image_size/load_offset are inconsistent with the first two members - please tidy so the comments line up. Also use u32/u64 for consistency with the rest of U-Boot. I have to wonder whether it would be OK to share this struct with RISC-V in a header file? > diff --git a/arch/loongarch/lib/image.c b/arch/loongarch/lib/image.c > @@ -0,0 +1,66 @@ > + /* To workaround kernel supplying DMW based virtual address */ > + ep_phys = TO_PHYS(lhdr->kernel_entry); > + *ep = *relocated_addr + (ep_phys - lhdr->load_offset); Please expand this comment - from context it looks like kernel_entry is a DMW virtual address, and you are converting to a physical offset within the image and re-basing onto the relocated load address. Spell that out, with a pointer to the relevant paragraph of the booting spec. Regards, Simon
