console: Implement pre-console buffer
Allow redirection of console output prior to console initialisation to a
temporary buffer.
To enable this functionality, the board (or arch) must define:
- CONFIG_PRE_CONSOLE_BUFFER - Enable pre-console buffer
- CONFIG_PRE_CON_BUF_ADDR - Base address of pre-console buffer
- CONFIG_PRE_CON_BUF_SZ - Size of pre-console buffer (in bytes)
The pre-console buffer will buffer the last CONFIG_PRE_CON_BUF_SZ bytes
Any earlier characters are silently dropped.
diff --git a/common/console.c b/common/console.c
index b23d933..f17875e 100644
--- a/common/console.c
+++ b/common/console.c
@@ -329,6 +329,39 @@
return serial_tstc();
}
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+#define CIRC_BUF_IDX(idx) ((idx) % (unsigned long)CONFIG_PRE_CON_BUF_SZ)
+
+static void pre_console_putc(const char c)
+{
+ char *buffer = (char *)CONFIG_PRE_CON_BUF_ADDR;
+
+ buffer[CIRC_BUF_IDX(gd->precon_buf_idx++)] = c;
+}
+
+static void pre_console_puts(const char *s)
+{
+ while (*s)
+ pre_console_putc(*s++);
+}
+
+static void print_pre_console_buffer(void)
+{
+ unsigned long i = 0;
+ char *buffer = (char *)CONFIG_PRE_CON_BUF_ADDR;
+
+ if (gd->precon_buf_idx > CONFIG_PRE_CON_BUF_SZ)
+ i = gd->precon_buf_idx - CONFIG_PRE_CON_BUF_SZ;
+
+ while (i < gd->precon_buf_idx)
+ putc(buffer[CIRC_BUF_IDX(i++)]);
+}
+#else
+static inline void pre_console_putc(const char c) {}
+static inline void pre_console_puts(const char *s) {}
+static inline void print_pre_console_buffer(void) {}
+#endif
+
void putc(const char c)
{
#ifdef CONFIG_SILENT_CONSOLE
@@ -342,7 +375,7 @@
#endif
if (!gd->have_console)
- return;
+ return pre_console_putc(c);
if (gd->flags & GD_FLG_DEVINIT) {
/* Send to the standard output */
@@ -366,7 +399,7 @@
#endif
if (!gd->have_console)
- return;
+ return pre_console_puts(s);
if (gd->flags & GD_FLG_DEVINIT) {
/* Send to the standard output */
@@ -383,8 +416,10 @@
uint i;
char printbuffer[CONFIG_SYS_PBSIZE];
+#ifndef CONFIG_PRE_CONSOLE_BUFFER
if (!gd->have_console)
return 0;
+#endif
va_start(args, fmt);
@@ -404,8 +439,10 @@
uint i;
char printbuffer[CONFIG_SYS_PBSIZE];
+#ifndef CONFIG_PRE_CONSOLE_BUFFER
if (!gd->have_console)
return 0;
+#endif
/* For this to work, printbuffer must be larger than
* anything we ever want to print.
@@ -547,6 +584,8 @@
gd->flags |= GD_FLG_SILENT;
#endif
+ print_pre_console_buffer();
+
return 0;
}
