[PATCH 2/3] bootstrap_read_disk(): optionally inform the caller of the buffer size

[Sascha Hauer]

From: Ulrich Ölmann <u.oelmann at pengutronix.de>

The size of the buffer allocated in the function is needed if it shall be
inspected more closely later. Therefore optionally return it via a new pointer
argument.

Signed-off-by: Ulrich Ölmann <u.oelmann at pengutronix.de>
---
 arch/arm/mach-at91/bootstrap.c | 2 +-
 arch/arm/mach-socfpga/xload.c  | 2 +-
 include/bootstrap.h            | 4 ++--
 lib/bootstrap/disk.c           | 5 ++++-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-at91/bootstrap.c b/arch/arm/mach-at91/bootstrap.c
index 90b7b33fc9..0b1567cd23 100644
--- a/arch/arm/mach-at91/bootstrap.c
+++ b/arch/arm/mach-at91/bootstrap.c
@@ -89,7 +89,7 @@ static void at91bootstrap_boot_mmc(void)
 	kernel_entry_func func = NULL;
 
 	printf("Boot from mmc\n");
-	func = bootstrap_read_disk("disk0.0", NULL);
+	func = bootstrap_read_disk("disk0.0", NULL, NULL);
 	bootstrap_boot(func, false);
 	bootstrap_err("... failed\n");
 	free(func);
diff --git a/arch/arm/mach-socfpga/xload.c b/arch/arm/mach-socfpga/xload.c
index 8be2827e62..1131cfee41 100644
--- a/arch/arm/mach-socfpga/xload.c
+++ b/arch/arm/mach-socfpga/xload.c
@@ -37,7 +37,7 @@ static __noreturn int socfpga_xload(void)
 		socfpga_cyclone5_mmc_init();
 
 		for (part = barebox_parts; part->mmc_disk; part++) {
-			buf = bootstrap_read_disk(barebox_parts->mmc_disk, "fat");
+			buf = bootstrap_read_disk(barebox_parts->mmc_disk, "fat", NULL);
 			if (!buf) {
 				pr_info("failed to load barebox from MMC %s\n",
 					part->mmc_disk);
diff --git a/include/bootstrap.h b/include/bootstrap.h
index 8b3bb34a03..3e006d3cc9 100644
--- a/include/bootstrap.h
+++ b/include/bootstrap.h
@@ -25,9 +25,9 @@ static inline void* bootstrap_read_devfs(char *devname, bool use_bb, int offset,
 #endif
 
 #ifdef CONFIG_BOOTSTRAP_DISK
-void* bootstrap_read_disk(const char *devname, const char *fstype);
+void* bootstrap_read_disk(const char *devname, char *fstype, size_t *bufsize);
 #else
-static inline void* bootstrap_read_disk(const char *devname, const char *fstype)
+static inline void* bootstrap_read_disk(const char *devname, char *fstype, size_t *bufsize)
 {
 	return NULL;
 }
diff --git a/lib/bootstrap/disk.c b/lib/bootstrap/disk.c
index fd016166e6..ed8b1aa407 100644
--- a/lib/bootstrap/disk.c
+++ b/lib/bootstrap/disk.c
@@ -14,7 +14,7 @@
 #include <libfile.h>
 #include <bootstrap.h>
 
-void* bootstrap_read_disk(const char *dev, const char *fstype)
+void* bootstrap_read_disk(const char *dev, char *fstype, size_t *bufsize)
 {
 	int ret;
 	void *buf;
@@ -34,5 +34,8 @@ void* bootstrap_read_disk(const char *dev, const char *fstype)
 		return NULL;
 	}
 
+	if (bufsize)
+		*bufsize = len;
+
 	return buf;
 }
-- 
2.20.1