[PATCH v2 48/71] bootstd: Support reading the device tree with EFI
Mark Kettenis
mark.kettenis at xs4all.nl
Sun Jan 8 11:25:34 CET 2023
> From: Simon Glass <sjg at chromium.org>
> Date: Sat, 7 Jan 2023 19:50:24 -0700
>
> With EFI booting the device tree is required but is not actually specified
> in any way. The normal method is to use a fdtfile environment variable to
> get the filename, then look for that file on the media.
>
> Implement this in the bootmeth.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
Hi Simon,
The distroboot scripts also reads dtb files from the root directory of
the ESP (so without the "dtb/" prefix). This code needs to do that as
well otherwise some folks will run with a different device tree after
switching to bootstd.
The construction of a fallback dtb filename based on soc, board and
boardver is only done for (32-bit) arm and not for arm64. It isn't
done for riscv either. That feels to me like someone recognized that
was a bit of a mistake and shouldn't be done for modern targets. So I
think that code should be under the same
#if defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
as it is now in config_distro_bootcmd.h.
Cheers,
Mark
> (no changes since v1)
>
> boot/bootmeth_efi.c | 105 +++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 99 insertions(+), 6 deletions(-)
>
> diff --git a/boot/bootmeth_efi.c b/boot/bootmeth_efi.c
> index 77b4ba22470..53a0489b93c 100644
> --- a/boot/bootmeth_efi.c
> +++ b/boot/bootmeth_efi.c
> @@ -143,10 +143,32 @@ static int distro_efi_check(struct udevice *dev, struct bootflow_iter *iter)
> return 0;
> }
>
> +static void distro_efi_get_fdt_name(char *fname, int size)
> +{
> + const char *fdt_fname;
> +
> + fdt_fname = env_get("fdtfile");
> + if (fdt_fname) {
> + snprintf(fname, size, "dtb/%s", fdt_fname);
> + log_debug("Using device tree: %s\n", fname);
> + } else {
> + const char *soc = env_get("soc");
> + const char *board = env_get("board");
> + const char *boardver = env_get("boardver");
> +
> + /* cf the code in label_boot() which seems very complex */
> + snprintf(fname, size, "dtb/%s%s%s%s.dtb",
> + soc ? soc : "", soc ? "-" : "", board ? board : "",
> + boardver ? boardver : "");
> + log_debug("Using default device tree: %s\n", fname);
> + }
> +}
> +
> static int distro_efi_read_bootflow_file(struct udevice *dev,
> struct bootflow *bflow)
> {
> struct blk_desc *desc = NULL;
> + ulong fdt_addr, size;
> char fname[256];
> int ret;
>
> @@ -170,15 +192,43 @@ static int distro_efi_read_bootflow_file(struct udevice *dev,
> if (ret)
> return log_msg_ret("read", -EINVAL);
>
> + distro_efi_get_fdt_name(fname, sizeof(fname));
> + bflow->fdt_fname = strdup(fname);
> + if (!bflow->fdt_fname)
> + return log_msg_ret("fil", -ENOMEM);
> +
> + fdt_addr = env_get_hex("fdt_addr_r", 0);
> + ret = bootmeth_common_read_file(dev, bflow, fname, fdt_addr, &size);
> + if (!ret) {
> + bflow->fdt_size = size;
> + bflow->fdt_addr = fdt_addr;
> +
> + /*
> + * TODO: Apply extension overlay
> + *
> + * Here we need to load and apply the extension overlay. This is
> + * not implemented. See do_extension_apply(). The extension
> + * stuff needs an implementation in boot/extension.c so it is
> + * separate from the command code. Really the extension stuff
> + * should use the device tree and a uclass / driver interface
> + * rather than implementing its own list
> + */
> + } else {
> + log_debug("No device tree available\n");
> + }
> +
> return 0;
> }
>
> static int distro_efi_read_bootflow_net(struct bootflow *bflow)
> {
> - const char *addr_str;
> + char file_addr[17], fname[256];
> + char *tftp_argv[] = {"tftp", file_addr, fname, NULL};
> + struct cmd_tbl cmdtp = {}; /* dummy */
> + const char *addr_str, *fdt_addr_str;
> int ret, arch, size;
> + ulong addr, fdt_addr;
> char str[36];
> - ulong addr;
>
> ret = get_efi_pxe_vci(str, sizeof(str));
> if (ret)
> @@ -216,6 +266,25 @@ static int distro_efi_read_bootflow_net(struct bootflow *bflow)
> efi_set_bootdev("Net", "", bflow->fname, map_sysmem(addr, 0),
> bflow->size);
>
> + /* read the DT file also */
> + fdt_addr_str = env_get("fdt_addr_r");
> + if (!fdt_addr_str)
> + return log_msg_ret("fdt", -EINVAL);
> + fdt_addr = hextoul(fdt_addr_str, NULL);
> + sprintf(file_addr, "%lx", fdt_addr);
> +
> + distro_efi_get_fdt_name(fname, sizeof(fname));
> + bflow->fdt_fname = strdup(fname);
> + if (!bflow->fdt_fname)
> + return log_msg_ret("fil", -ENOMEM);
> +
> + if (!do_tftpb(&cmdtp, 0, 3, tftp_argv)) {
> + bflow->fdt_size = env_get_hex("filesize", 0);
> + bflow->fdt_addr = fdt_addr;
> + } else {
> + log_debug("No device tree available\n");
> + }
> +
> bflow->state = BOOTFLOWST_READY;
>
> return 0;
> @@ -243,15 +312,39 @@ static int distro_efi_read_bootflow(struct udevice *dev, struct bootflow *bflow)
>
> int distro_efi_boot(struct udevice *dev, struct bootflow *bflow)
> {
> + ulong kernel, fdt;
> char cmd[50];
>
> + /* A non-zero buffer indicates the kernel is there */
> + if (bflow->buf) {
> + kernel = (ulong)map_to_sysmem(bflow->buf);
> +
> + /*
> + * use the provided device tree if available, else fall back to
> + * the control FDT
> + */
> + if (bflow->fdt_fname)
> + fdt = bflow->fdt_addr;
> + else
> + fdt = (ulong)map_to_sysmem(gd->fdt_blob);
> + } else {
> + /*
> + * This doesn't actually work for network devices:
> + *
> + * do_bootefi_image() No UEFI binary known at 0x02080000
> + *
> + * But this is the same behaviour for distro boot, so it can be
> + * fixed here.
> + */
> + kernel = env_get_hex("kernel_addr_r", 0);
> + fdt = env_get_hex("fdt_addr_r", 0);
> + }
> +
> /*
> * At some point we can add a real interface to bootefi so we can call
> - * this directly. For now, go through the CLI like distro boot.
> + * this directly. For now, go through the CLI, like distro boot.
> */
> - snprintf(cmd, sizeof(cmd), "bootefi %lx %lx",
> - (ulong)map_to_sysmem(bflow->buf),
> - (ulong)map_to_sysmem(gd->fdt_blob));
> + snprintf(cmd, sizeof(cmd), "bootefi %lx %lx", kernel, fdt);
> if (run_command(cmd, 0))
> return log_msg_ret("run", -EINVAL);
>
> --
> 2.39.0.314.g84b9a713c41-goog
>
>
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