[U-Boot] [PATCH v3 06/17] sandbox: Add CONFIG_OF_HOSTFILE to read FDT from host file

[Simon Glass]

With sandbox it is tricky to add an FDT to the image at build time (or
later) since we build an ELF file, not a plain binary, and the address
space of the whole U-Boot is not accessible in the emulated memory map
of sandbox.

Sandbox can read files directly from the host, though, so add an option
to read an FDT from a host file on start-up.

Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v3:
- Add CONFIG_OF_HOSTFILE support to generic board instead of sandbox

Changes in v2:
- Fix typo "os defined" -> "is defined"
- Use gd->arch.ram_buf instead of gd->ram_buf (now that generic board is in)
- Fix checkpatch warnings about split strings

 arch/sandbox/cpu/start.c         |  7 +++++
 arch/sandbox/include/asm/state.h |  1 +
 common/board_f.c                 | 55 ++++++++++++++++++++++++++++++++++++++++
 doc/README.fdt-control           |  6 ++++-
 include/configs/sandbox.h        |  2 ++
 5 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 5287fd5..2fcec8b 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -104,6 +104,13 @@ static int sb_cmdline_cb_command(struct sandbox_state *state, const char *arg)
 }
 SB_CMDLINE_OPT_SHORT(command, 'c', 1, "Execute U-Boot command");
 
+static int sb_cmdline_cb_fdt(struct sandbox_state *state, const char *arg)
+{
+	state->fdt_fname = arg;
+	return 0;
+}
+SB_CMDLINE_OPT_SHORT(fdt, 'd', 1, "Specify U-Boot's control FDT");
+
 int main(int argc, char *argv[])
 {
 	struct sandbox_state *state;
diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h
index 2b62b46..9552708 100644
--- a/arch/sandbox/include/asm/state.h
+++ b/arch/sandbox/include/asm/state.h
@@ -34,6 +34,7 @@ enum exit_type_id {
 /* The complete state of the test system */
 struct sandbox_state {
 	const char *cmd;		/* Command to execute */
+	const char *fdt_fname;		/* Filename of FDT binary */
 	enum exit_type_id exit_type;	/* How we exited U-Boot */
 	const char *parse_err;		/* Error to report from parsing */
 	int argc;			/* Program arguments */
diff --git a/common/board_f.c b/common/board_f.c
index 2045055..3a6638f 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -31,6 +31,7 @@
 #include <version.h>
 #include <environment.h>
 #include <fdtdec.h>
+#include <fs.h>
 #if defined(CONFIG_CMD_IDE)
 #include <ide.h>
 #endif
@@ -305,6 +306,55 @@ __weak int arch_cpu_init(void)
 	return 0;
 }
 
+#ifdef CONFIG_OF_HOSTFILE
+
+#define CHECK(x)		err = (x); if (err) goto failed;
+
+/* Create an empty device tree blob */
+static int make_empty_fdt(void *fdt)
+{
+	int err;
+
+	CHECK(fdt_create(fdt, 256));
+	CHECK(fdt_finish_reservemap(fdt));
+	CHECK(fdt_begin_node(fdt, ""));
+	CHECK(fdt_end_node(fdt));
+	CHECK(fdt_finish(fdt));
+
+	return 0;
+failed:
+	printf("Unable to create empty FDT: %s\n", fdt_strerror(err));
+	return -EACCES;
+}
+
+static int read_fdt_from_file(void)
+{
+	struct sandbox_state *state = state_get_current();
+	void *blob;
+	int size;
+	int err;
+
+	blob = map_sysmem(CONFIG_SYS_FDT_LOAD_ADDR, 0);
+	if (!state->fdt_fname) {
+		err = make_empty_fdt(blob);
+		if (!err)
+			goto done;
+		return err;
+	}
+	err = fs_set_blk_dev("host", NULL, FS_TYPE_SANDBOX);
+	if (err)
+		return err;
+	size = fs_read(state->fdt_fname, CONFIG_SYS_FDT_LOAD_ADDR, 0, 0);
+	if (size < 0)
+		return -EIO;
+
+done:
+	gd->fdt_blob = blob;
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_SANDBOX
 static int setup_ram_buf(void)
 {
@@ -328,6 +378,11 @@ static int setup_fdt(void)
 # else
 	gd->fdt_blob = (ulong *)&_end;
 # endif
+#elif defined(CONFIG_OF_HOSTFILE)
+	if (read_fdt_from_file()) {
+		puts("Failed to read control FDT\n");
+		return -1;
+	}
 #endif
 	/* Allow the early environment to override the fdt address */
 	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index 8352835..5963f78 100644
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -142,7 +142,11 @@ join the two:
 
 and then flash image.bin onto your board.
 
-You cannot use both of these options at the same time.
+If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on
+startup. This is only useful for sandbox. Use the -d flag to U-Boot to
+specify the file to read.
+
+You cannot use more than one of these options at the same time.
 
 If you wish to put the fdt at a different address in memory, you can
 define the "fdtcontroladdr" environment variable. This is the hex
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index da7cc9a..8efaded 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -26,6 +26,7 @@
 #define CONFIG_SANDBOX_BITS_PER_LONG	64
 
 #define CONFIG_OF_CONTROL
+#define CONFIG_OF_HOSTFILE
 #define CONFIG_OF_LIBFDT
 #define CONFIG_LMB
 
@@ -71,6 +72,7 @@
 #define CONFIG_SYS_MEMTEST_START	0x00100000
 #define CONFIG_SYS_MEMTEST_END		(CONFIG_SYS_MEMTEST_START + 0x1000)
 #define CONFIG_PHYS_64BIT
+#define CONFIG_SYS_FDT_LOAD_ADDR	0x1000000
 
 /* Size of our emulated memory */
 #define CONFIG_SYS_SDRAM_BASE		0
-- 
1.8.2.1