[U-Boot] [PATCH v2 1/2] efi_loader: Pass fdt address directly to bootefi cmd

[Alexander Graf]

The bootefi cmd today fetches its device tree pointer from either the
location appointed by "fdt addr" with a fallback to the U-Boot control
fdt.

This integration is unusual for U-Boot and diverges from the way we
usually handle parameters to boot commands. So let's pass the fdt
directly into the bootefi command instead and move the control fdt
logic into the distro boot script.

Signed-off-by: Alexander Graf <agraf at suse.de>

---

v1 -> v2:

  - Make fdt parameter optional
  - Explain fdt parameter more technically
  - Fix whitespace
---
 cmd/bootefi.c                   | 36 ++++++++++++++++--------------------
 include/config_distro_bootcmd.h |  9 ++++++---
 2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index b213ef1..7f552fc 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -142,12 +142,11 @@ static void *copy_fdt(void *fdt)
  * Load an EFI payload into a newly allocated piece of memory, register all
  * EFI objects it would want to access and jump to it.
  */
-static unsigned long do_bootefi_exec(void *efi)
+static unsigned long do_bootefi_exec(void *efi, void *fdt)
 {
 	ulong (*entry)(void *image_handle, struct efi_system_table *st);
 	ulong fdt_pages, fdt_size, fdt_start, fdt_end;
 	bootm_headers_t img = { 0 };
-	void *fdt = working_fdt;
 
 	/*
 	 * gd lives in a fixed register which may get clobbered while we execute
@@ -155,13 +154,7 @@ static unsigned long do_bootefi_exec(void *efi)
 	 */
 	efi_save_gd();
 
-	/* Update system table to point to our currently loaded FDT */
-
-	/* Fall back to included fdt if none was manually loaded */
-	if (!fdt && gd->fdt_blob)
-		fdt = (void *)gd->fdt_blob;
-
-	if (fdt) {
+	if (fdt && !fdt_check_header(fdt)) {
 		/* Prepare fdt for payload */
 		fdt = copy_fdt(fdt);
 
@@ -185,7 +178,7 @@ static unsigned long do_bootefi_exec(void *efi)
 		efi_add_memory_map(fdt_start, fdt_pages,
 				   EFI_BOOT_SERVICES_DATA, true);
 	} else {
-		printf("WARNING: No device tree loaded, expect boot to fail\n");
+		printf("WARNING: Invalid device tree, expect boot to fail\n");
 		systab.nr_tables = 0;
 	}
 
@@ -216,8 +209,8 @@ static unsigned long do_bootefi_exec(void *efi)
 /* Interpreter command to boot an arbitrary EFI image from memory */
 static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
-	char *saddr;
-	unsigned long addr;
+	char *saddr, *sfdt;
+	unsigned long addr, fdt_addr = 0;
 	int r = 0;
 
 	if (argc < 2)
@@ -226,8 +219,13 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 	addr = simple_strtoul(saddr, NULL, 16);
 
+	if (argc > 2) {
+		sfdt = argv[2];
+		fdt_addr = simple_strtoul(sfdt, NULL, 16);
+	}
+
 	printf("## Starting EFI application at 0x%08lx ...\n", addr);
-	r = do_bootefi_exec((void *)addr);
+	r = do_bootefi_exec((void *)addr, (void*)fdt_addr);
 	printf("## Application terminated, r = %d\n", r);
 
 	if (r != 0)
@@ -238,16 +236,14 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 #ifdef CONFIG_SYS_LONGHELP
 static char bootefi_help_text[] =
-	"<image address>\n"
-	"  - boot EFI payload stored at address <image address>\n"
-	"\n"
-	"Since most EFI payloads want to have a device tree provided, please\n"
-	"make sure you load a device tree using the fdt addr command before\n"
-	"executing bootefi.\n";
+	"<image address> [fdt address]\n"
+	"  - boot EFI payload stored at address <image address>.\n"
+	"    If specified, the device tree located at <fdt address> gets\n"
+	"    exposed as EFI configuration table.\n";
 #endif
 
 U_BOOT_CMD(
-	bootefi, 2, 0, do_bootefi,
+	bootefi, 3, 0, do_bootefi,
 	"Boots an EFI payload from memory\n",
 	bootefi_help_text
 );
diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
index ad9045e..dddebc3 100644
--- a/include/config_distro_bootcmd.h
+++ b/include/config_distro_bootcmd.h
@@ -103,12 +103,15 @@
 	"boot_efi_binary="                                                \
 		"load ${devtype} ${devnum}:${distro_bootpart} "           \
 			"${kernel_addr_r} efi/boot/"BOOTEFI_NAME"; "      \
-		"bootefi ${kernel_addr_r}\0"                              \
+		"if fdt addr ${fdt_addr_r}; then "                        \
+			"bootefi ${kernel_addr_r} ${fdt_addr_r};"         \
+		"else"                                                    \
+			"bootefi ${kernel_addr_r} ${fdtcontroladdr};"     \
+		"fi\0"                                                    \
 	\
 	"load_efi_dtb="                                                   \
 		"load ${devtype} ${devnum}:${distro_bootpart} "           \
-			"${fdt_addr_r} ${prefix}${fdtfile}; "             \
-		"fdt addr ${fdt_addr_r}\0"                                \
+			"${fdt_addr_r} ${prefix}${fdtfile}\0"             \
 	\
 	"efi_dtb_prefixes=/ /dtb/ /dtb/current/\0"                        \
 	"scan_dev_for_efi="                                               \
-- 
1.8.5.6