SPL: tiny-printf: avoid any BSS usage

[u-boot] / lib / tiny-printf.c

diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c
index 6766a8f1c8b648a201f430b15116dbf69c8a096e..b334f053cc0ee2645aa3669701f0ec22419bb572 100644 (file)
--- a/lib/tiny-printf.c
+++ b/lib/tiny-printf.c
@@ -13,8 +13,16 @@
 #include <stdarg.h>
 #include <serial.h>
 
-static char *bf;
-static char zs;
+/*
+ * This code in here may execute before the DRAM is initialised, so
+ * we should make sure that it doesn't touch BSS, which some boards
+ * put in DRAM.
+ */
+static char *bf __attribute__ ((section(".data")));
+static char zs __attribute__ ((section(".data")));
+
+/* Current position in sprintf() output string */
+static char *outstr __attribute__ ((section(".data")));
 
 static void out(char c)
 {
@@ -40,23 +48,20 @@ static void div_out(unsigned int *num, unsigned int div)
                out_dgt(dgt);
 }
 
-int printf(const char *fmt, ...)
+int _vprintf(const char *fmt, va_list va, void (*putc)(const char ch))
 {
-       va_list va;
        char ch;
        char *p;
        unsigned int num;
        char buf[12];
        unsigned int div;
 
-       va_start(va, fmt);
-
        while ((ch = *(fmt++))) {
                if (ch != '%') {
                        putc(ch);
                } else {
-                       char lz = 0;
-                       char w = 0;
+                       bool lz = false;
+                       int width = 0;
 
                        ch = *(fmt++);
                        if (ch == '0') {
@@ -65,9 +70,9 @@ int printf(const char *fmt, ...)
                        }
 
                        if (ch >= '0' && ch <= '9') {
-                               w = 0;
+                               width = 0;
                                while (ch >= '0' && ch <= '9') {
-                                       w = (w * 10) + ch - '0';
+                                       width = (width * 10) + ch - '0';
                                        ch = *fmt++;
                                }
                        }
@@ -76,7 +81,7 @@ int printf(const char *fmt, ...)
                        zs = 0;
 
                        switch (ch) {
-                       case 0:
+                       case '\0':
                                goto abort;
                        case 'u':
                        case 'd':
@@ -85,13 +90,21 @@ int printf(const char *fmt, ...)
                                        num = -(int)num;
                                        out('-');
                                }
-                               for (div = 1000000000; div; div /= 10)
-                                       div_out(&num, div);
+                               if (!num) {
+                                       out_dgt(0);
+                               } else {
+                                       for (div = 1000000000; div; div /= 10)
+                                               div_out(&num, div);
+                               }
                                break;
                        case 'x':
                                num = va_arg(va, unsigned int);
-                               for (div = 0x10000000; div; div /= 0x10)
-                                       div_out(&num, div);
+                               if (!num) {
+                                       out_dgt(0);
+                               } else {
+                                       for (div = 0x10000000; div; div /= 0x10)
+                                               div_out(&num, div);
+                               }
                                break;
                        case 'c':
                                out((char)(va_arg(va, int)));
@@ -107,16 +120,68 @@ int printf(const char *fmt, ...)
 
                        *bf = 0;
                        bf = p;
-                       while (*bf++ && w > 0)
-                               w--;
-                       while (w-- > 0)
+                       while (*bf++ && width > 0)
+                               width--;
+                       while (width-- > 0)
                                putc(lz ? '0' : ' ');
-                       while ((ch = *p++))
-                               putc(ch);
+                       if (p) {
+                               while ((ch = *p++))
+                                       putc(ch);
+                       }
                }
        }
 
 abort:
-       va_end(va);
        return 0;
 }
+
+int vprintf(const char *fmt, va_list va)
+{
+       return _vprintf(fmt, va, putc);
+}
+
+int printf(const char *fmt, ...)
+{
+       va_list va;
+       int ret;
+
+       va_start(va, fmt);
+       ret = _vprintf(fmt, va, putc);
+       va_end(va);
+
+       return ret;
+}
+
+static void putc_outstr(char ch)
+{
+       *outstr++ = ch;
+}
+
+int sprintf(char *buf, const char *fmt, ...)
+{
+       va_list va;
+       int ret;
+
+       va_start(va, fmt);
+       outstr = buf;
+       ret = _vprintf(fmt, va, putc_outstr);
+       va_end(va);
+       *outstr = '\0';
+
+       return ret;
+}
+
+/* Note that size is ignored */
+int snprintf(char *buf, size_t size, const char *fmt, ...)
+{
+       va_list va;
+       int ret;
+
+       va_start(va, fmt);
+       outstr = buf;
+       ret = _vprintf(fmt, va, putc_outstr);
+       va_end(va);
+       *outstr = '\0';
+
+       return ret;
+}