[PATCH] command: add FDT setup for bootelf by flag

[Maxim Moskalets]

Added the ability to use FDT for ELF applications, required to run some OS. To 
make FDT setup, you need to set the elf_needed_fdt environment variable to a 
value like y or yes.

Signed-off-by: Maxim Moskalets <maxim.moskal...@kaspersky.com>

Cc: Tom Rini <tr...@konsulko.com>
---

 cmd/elf.c     | 14 ++++++++++++++
 env/common.c  |  5 +++++
 include/env.h |  7 +++++++
 3 files changed, 26 insertions(+)

diff --git a/cmd/elf.c b/cmd/elf.c
index b7b9f506a5..4d365771eb 100644
--- a/cmd/elf.c
+++ b/cmd/elf.c
@@ -38,6 +38,8 @@ static unsigned long do_bootelf_exec(ulong (*entry)(int, char 
* const[]),
 /* Interpreter command to boot an arbitrary ELF image from memory */
 int do_bootelf(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
+       unsigned long fdt_addr;
+       struct bootm_headers img = { 0 };
        unsigned long addr; /* Address of the ELF image */
        unsigned long rc; /* Return value from user code */
        char *sload = NULL;
@@ -68,6 +70,18 @@ int do_bootelf(struct cmd_tbl *cmdtp, int flag, int argc, 
char *const argv[])
        else
                addr = load_elf_image_shdr(addr);
 
+       if (!env_get_elf_need_fdt()) {
+               if (argc >= 1 && strict_strtoul(argv[0], 16, &fdt_addr) != 
-EINVAL) {
+                       printf("Got FDT at 0x%08lx ...\n", fdt_addr);
+
+                       if (image_setup_libfdt(&img, (void *)fdt_addr, 0, 
NULL)) {
+                               printf("ERROR: Failed to process device 
tree\n");
+                               return 1;
+                       }
+               }
+       }
+
+
        if (!env_get_autostart())
                return rcode;
 
diff --git a/env/common.c b/env/common.c
index 48a565107c..8cd8558c3f 100644
--- a/env/common.c
+++ b/env/common.c
@@ -346,6 +346,11 @@ bool env_get_autostart(void)
        return env_get_yesno("autostart") == 1;
 }
 
+bool env_get_elf_need_fdt(void)
+{
+       return env_get_yesno("elf_need_fdt") == 1;
+}
+
 /*
  * Look up the variable from the default environment
  */
diff --git a/include/env.h b/include/env.h
index d2a5954ded..384c312d2e 100644
--- a/include/env.h
+++ b/include/env.h
@@ -148,6 +148,13 @@ int env_get_yesno(const char *var);
  */
 bool env_get_autostart(void);
 
+/**
+ * env_get_elf_need_fdt() - Check if FDT is needed for ELF image
+ *
+ * Return: true if the "elf_need_fdt" env var exists and is set to "yes"
+ */
+bool env_get_elf_need_fdt(void);
+
 /**
  * env_set() - set an environment variable
  *
-- 
2.39.2