[U-Boot] [PATCH v3 1/1] efi_loader: rework fdt handling in distro boot script

[AKASHI Takahiro]

The current scenario for default UEFI booting, scan_dev_for_efi, has
several issues:
* load dtb dynamically even if its loacation (device) is not the same
  as BOOTEFI_NAME binary's, (reported by Alex)
* invoke 'bootmgr' only if BOOTEFI_NAME binary does exit even though
  'bootmgr' can and should work independently whether or not the binary
  exist,
* in addition, invoke 'bootmgr' with dynamically-loaded dtb.
  This behavior is not expected. (reported by Alex)
* always assume that a 'fdtfile' variable is defined,
  ("test -e ${devtype} ${devnum}:${distro_bootpart} "${prefix}${efi_fdtfile}"
  always returns true even if fdtfile is NULL with prefix=="/".)
* redundantly check for 'fdt_addr_r' in boot_efi_binary

In this patch, all the issues above are sorted out.
Please note that the default behavior can be customized with:
	fdtfile: a dtb file name
	efi_dtb_prefixes: a list of paths for searching for a dtb file

(this feature does work even without this patch.)

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 include/config_distro_bootcmd.h | 38 +++++++++++++++++----------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
index 373fee78a999..256698309eb9 100644
--- a/include/config_distro_bootcmd.h
+++ b/include/config_distro_bootcmd.h
@@ -115,7 +115,7 @@
  */
 #define BOOTENV_EFI_SET_FDTFILE_FALLBACK                                  \
 	"if test -z \"${fdtfile}\" -a -n \"${soc}\"; then "               \
-	  "setenv efi_fdtfile ${soc}-${board}${boardver}.dtb; "           \
+	  "efi_fdtfile=${soc}-${board}${boardver}.dtb; "           \
 	"fi; "
 #else
 #define BOOTENV_EFI_SET_FDTFILE_FALLBACK
@@ -124,26 +124,20 @@
 
 #define BOOTENV_SHARED_EFI                                                \
 	"boot_efi_binary="                                                \
-		"if fdt addr ${fdt_addr_r}; then "                        \
-			"bootefi bootmgr ${fdt_addr_r};"                  \
-		"else "                                                   \
-			"bootefi bootmgr ${fdtcontroladdr};"              \
-		"fi;"                                                     \
 		"load ${devtype} ${devnum}:${distro_bootpart} "           \
 			"${kernel_addr_r} efi/boot/"BOOTEFI_NAME"; "      \
-		"if fdt addr ${fdt_addr_r}; then "                        \
-			"bootefi ${kernel_addr_r} ${fdt_addr_r};"         \
-		"else "                                                   \
-			"bootefi ${kernel_addr_r} ${fdtcontroladdr};"     \
-		"fi\0"                                                    \
+		"bootefi ${kernel_addr_r} ${efi_fdt_addr};\0"		  \
 	\
 	"load_efi_dtb="                                                   \
-		"load ${devtype} ${devnum}:${distro_bootpart} "           \
-			"${fdt_addr_r} ${prefix}${efi_fdtfile}\0"         \
+		"load ${devtype} ${devnum}:${distro_bootpart} "		  \
+			"${fdt_addr_r} ${prefix}${efi_fdtfile}; "	  \
+		"if fdt addr ${fdt_addr_r}; then "			  \
+			"efi_fdt_addr=${fdt_addr_r}; "			  \
+		"fi;\0"							  \
 	\
 	"efi_dtb_prefixes=/ /dtb/ /dtb/current/\0"                        \
-	"scan_dev_for_efi="                                               \
-		"setenv efi_fdtfile ${fdtfile}; "                         \
+	"set_efi_fdt_addr="						  \
+		"efi_fdtfile=${fdtfile}; "                         \
 		BOOTENV_EFI_SET_FDTFILE_FALLBACK                          \
 		"for prefix in ${efi_dtb_prefixes}; do "                  \
 			"if test -e ${devtype} "                          \
@@ -151,19 +145,26 @@
 					"${prefix}${efi_fdtfile}; then "  \
 				"run load_efi_dtb; "                      \
 			"fi;"                                             \
-		"done;"                                                   \
+		"done;\0"                                                   \
+	\
+	"scan_dev_for_efi="                                               \
 		"if test -e ${devtype} ${devnum}:${distro_bootpart} "     \
 					"efi/boot/"BOOTEFI_NAME"; then "  \
 				"echo Found EFI removable media binary "  \
 					"efi/boot/"BOOTEFI_NAME"; "       \
+				"efi_fdt_addr=${fdtcontroladdr}; "	  \
+				"if test -n \"${fdtfile}\"; then "	  \
+					"run set_efi_fdt_addr; "	  \
+				"fi; "					  \
 				"run boot_efi_binary; "                   \
 				"echo EFI LOAD FAILED: continuing...; "   \
-		"fi; "                                                    \
-		"setenv efi_fdtfile\0"
+		"fi;\0"
 #define SCAN_DEV_FOR_EFI "run scan_dev_for_efi;"
+#define BOOT_EFI_BOOT_MANAGER "bootefi bootmgr;"
 #else
 #define BOOTENV_SHARED_EFI
 #define SCAN_DEV_FOR_EFI
+#define BOOT_EFI_BOOT_MANAGER
 #endif
 
 #ifdef CONFIG_SATA
@@ -409,6 +410,7 @@
 	BOOT_TARGET_DEVICES(BOOTENV_DEV)                                  \
 	\
 	"distro_bootcmd=" BOOTENV_SET_SCSI_NEED_INIT                      \
+		BOOT_EFI_BOOT_MANAGER					  \
 		"for target in ${boot_targets}; do "                      \
 			"run bootcmd_${target}; "                         \
 		"done\0"
-- 
2.19.1