boot: Support a fake go with pxe

Provide a way to pass the 'fake go' flag from the bootflow flag through
to the PXE implementation, so that a request for a fake go
(via 'bootflow boot -f') is handled correctly in the bootmeth and when
booting.

Add a little more debugging of this in PXE.

Signed-off-by: Simon Glass <sjg@chromium.org>

boot/ext_pxe_common.c

@@ -89,6 +89,9 @@ static int extlinux_setup(struct udevice *dev, struct bootflow *bflow,
 			    false, plat->use_fallback, bflow);
 	if (ret)
 		return log_msg_ret("ctx", ret);
+	log_debug("bootfl flags %x\n", bflow->flags);
+	if (bflow->flags & BOOTFLOWF_FAKE_GO)
+		ctx->fake_go = true;
 
 	return 0;
 }
@@ -103,6 +106,7 @@ int extlinux_boot(struct udevice *dev, struct bootflow *bflow,
 
 	/* if we have already selected a label, just boot it */
 	if (plat->ctx.label) {
+		plat->ctx.fake_go = bflow->flags & BOOTFLOWF_FAKE_GO;
 		ret = pxe_do_boot(&plat->ctx);
 	} else {
 		ret = extlinux_setup(dev, bflow, getfile, allow_abs_path,

boot/pxe_utils.c

@@ -427,6 +427,11 @@ skip_overlay:
 static int label_process_fdt(struct pxe_context *ctx, struct pxe_label *label,
 			     char *kernel_addr, const char **fdt_argp)
 {
+	log_debug("label '%s' kernel_addr '%s' label->fdt '%s' fdtdir '%s' "
+		  "kernel_label '%s' fdt_argp '%s'\n",
+		  label->name, kernel_addr, label->fdt, label->fdtdir,
+		  label->kernel_label, *fdt_argp);
+
 	/* For FIT, the label can be identical to kernel one */
 	if (label->fdt && !strcmp(label->kernel_label, label->fdt)) {
 		*fdt_argp = kernel_addr;
@@ -594,7 +599,11 @@ static int label_run_boot(struct pxe_context *ctx, struct pxe_label *label,
 		int states;
 
 		states = ctx->restart ? BOOTM_STATE_RESTART : BOOTM_STATE_START;
-		log_debug("using bootm\n");
+		log_debug("using bootm fake_go=%d\n", ctx->fake_go);
+		if (ctx->fake_go)
+			states |= BOOTM_STATE_OS_FAKE_GO;
+		else
+			states |= BOOTM_STATE_OS_GO;
 		ret = boot_run(&bmi, "ext", states | BOOTM_STATE_FINDOS |
 			BOOTM_STATE_PRE_LOAD | BOOTM_STATE_FINDOTHER |
 			BOOTM_STATE_LOADOS);
@@ -782,8 +791,10 @@ static int label_boot(struct pxe_context *ctx, struct pxe_label *label)
 
 	if (!conf_fdt_str) {
 		if (!IS_ENABLED(CONFIG_SUPPORT_PASSING_ATAGS) ||
-		    strcmp("-", label->fdt))
+		    strcmp("-", label->fdt)) {
 			conf_fdt_str = env_get("fdt_addr");
+			log_debug("using fdt_addr '%s'\n", conf_fdt_str);
+		}
 	}
 
 	if (!conf_fdt_str) {
@@ -792,13 +803,17 @@ static int label_boot(struct pxe_context *ctx, struct pxe_label *label)
 		buf = map_sysmem(kern_addr, 0);
 		if (genimg_get_format(buf) != IMAGE_FORMAT_FIT) {
 			if (!IS_ENABLED(CONFIG_SUPPORT_PASSING_ATAGS) ||
-			    strcmp("-", label->fdt))
+			    strcmp("-", label->fdt)) {
 				conf_fdt_str = env_get("fdtcontroladdr");
+				log_debug("using fdtcontroladdr '%s'\n",
+					  conf_fdt_str);
+			}
 		}
 		unmap_sysmem(buf);
 	}
 	if (conf_fdt_str)
 		conf_fdt = hextoul(conf_fdt_str, NULL);
+	log_debug("conf_fdt %lx\n", conf_fdt);
 
 	if (ctx->bflow && conf_fdt_str)
 		ctx->bflow->fdt_addr = conf_fdt;

include/pxe_utils.h

@@ -135,6 +135,7 @@ typedef int (*pxe_getfile_func)(struct pxe_context *ctx, const char *file_path,
  * @conf_fdt: FDT address
  * @restart: true to use BOOTM_STATE_RESTART instead of BOOTM_STATE_START (only
  *	supported with FIT / bootm)
+ * @fake_go: Do a 'fake' boot, up to the last possible point, then return
  */
 struct pxe_context {
 	/**
@@ -170,6 +171,7 @@ struct pxe_context {
 	char *conf_fdt_str;
 	ulong conf_fdt;
 	bool restart;
+	bool fake_go;
 };
 
 /**