bootstd: Support reading the device tree with EFI

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@chromium.org>

diff --git a/boot/bootmeth_efi.c b/boot/bootmeth_efi.c
index 77b4ba2..53a0489 100644 (file)
--- 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);