[PATCH 06/17] arm: smh: Use numeric modes for smh_open

[Sean Anderson <sean.anderson@seco.com>]

There's no point in using string constants for smh_open if we are just
going to have to parse them. Instead, use numeric modes. The user needs
to be a bit careful with these, since they are much closer semantically
to string modes used by fopen(3) than the numeric modes used with
open(2).

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

 arch/arm/lib/semihosting.c | 21 +++------------------
 include/semihosting.h      | 25 ++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index c38892fdd8..b983cc3935 100644
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -22,9 +22,6 @@
 #define SYSREAD		0x06
 #define SYSFLEN		0x0C
 
-#define MODE_READ	0x0
-#define MODE_READBIN	0x1
-
 /*
  * Call the handler
  */
@@ -46,28 +43,16 @@ static noinline long smh_trap(unsigned int sysnum, void *addr)
  * Open a file on the host. Mode is "r" or "rb" currently. Returns a file
  * descriptor or -1 on error.
  */
-long smh_open(const char *fname, char *modestr)
+long smh_open(const char *fname, enum smh_open_mode mode)
 {
 	long fd;
-	unsigned long mode;
 	struct smh_open_s {
 		const char *fname;
 		unsigned long mode;
 		size_t len;
 	} open;
 
-	debug("%s: file \'%s\', mode \'%s\'\n", __func__, fname, modestr);
-
-	/* Check the file mode */
-	if (!(strcmp(modestr, "r"))) {
-		mode = MODE_READ;
-	} else if (!(strcmp(modestr, "rb"))) {
-		mode = MODE_READBIN;
-	} else {
-		printf("%s: ERROR mode \'%s\' not supported\n", __func__,
-		       modestr);
-		return -1;
-	}
+	debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
 
 	open.fname = fname;
 	open.len = strlen(fname);
@@ -155,7 +140,7 @@ static int smh_load_file(const char * const name, ulong load_addr,
 	long len;
 	long ret;
 
-	fd = smh_open(name, "rb");
+	fd = smh_open(name, MODE_READ | MODE_BINARY);
 	if (fd == -1)
 		return -1;
 
diff --git a/include/semihosting.h b/include/semihosting.h
index 3843863046..cf54819192 100644
--- a/include/semihosting.h
+++ b/include/semihosting.h
@@ -6,7 +6,30 @@
 #ifndef _SEMIHOSTING_H
 #define _SEMIHOSTING_H
 
-long smh_open(const char *fname, char *modestr);
+/**
+ * enum smh_open_mode - Numeric file modes for use with smh_open()
+ * MODE_READ: 'r'
+ * MODE_BINARY: 'b'
+ * MODE_PLUS: '+'
+ * MODE_WRITE: 'w'
+ * MODE_APPEND: 'a'
+ *
+ * These modes represent the mode string used by fopen(3) in a form which can
+ * be passed to smh_open(). These do NOT correspond directly to %O_RDONLY,
+ * %O_CREAT, etc; see fopen(3) for details. In particular, @MODE_PLUS
+ * effectively results in adding %O_RDWR, and @MODE_WRITE will add %O_TRUNC.
+ * For compatibility, @MODE_BINARY should be added when opening non-text files
+ * (such as images).
+ */
+enum smh_open_mode {
+	MODE_READ	= 0x0,
+	MODE_BINARY	= 0x1,
+	MODE_PLUS	= 0x2,
+	MODE_WRITE	= 0x4,
+	MODE_APPEND	= 0x8,
+};
+
+long smh_open(const char *fname, enum smh_open_mode mode);
 long smh_read(long fd, void *memp, size_t len);
 long smh_close(long fd);
 long smh_flen(long fd);
-- 
2.25.1