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/README b/README
index 91b6695..dfc7ada 100644 (file)
--- a/README
+++ b/README
@@ -619,6 +619,20 @@ The following options need to be configured:
                must be defined, to setup the maximum idle timeout for
                the SMC.
 
+- Pre-Console Buffer:
+                Prior to the console being initialised (i.e. serial UART
+                initialised etc) all console output is silently discarded.
+                Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
+                buffer any console messages prior to the console being
+                initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
+                bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
+                a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
+                bytes are output before the console is  initialised, the
+                earlier bytes are discarded.
+
+                'Sane' compilers will generate smaller code if
+                CONFIG_PRE_CON_BUF_SZ is a power of 2
+
 - Boot Delay:  CONFIG_BOOTDELAY - in seconds
                Delay before automatically booting the default image;
                set to -1 to disable autoboot.

diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 4fc51fd..b85b7fe 100644 (file)
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -38,6 +38,9 @@ typedef       struct  global_data {
        unsigned long   flags;
        unsigned long   baudrate;
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        unsigned long   env_addr;       /* Address  of Environment struct */
        unsigned long   env_valid;      /* Checksum of Environment valid? */
        unsigned long   fb_base;        /* base address of frame buffer */

diff --git a/arch/avr32/include/asm/global_data.h b/arch/avr32/include/asm/global_data.h
index 4ef8fc5..5c654bd 100644 (file)
--- a/arch/avr32/include/asm/global_data.h
+++ b/arch/avr32/include/asm/global_data.h
@@ -38,6 +38,9 @@ typedef       struct  global_data {
        unsigned long   baudrate;
        unsigned long   stack_end;      /* highest stack address */
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        unsigned long   reloc_off;      /* Relocation Offset */
        unsigned long   env_addr;       /* Address of env struct */
        unsigned long   env_valid;      /* Checksum of env valid? */

diff --git a/arch/blackfin/include/asm/global_data.h b/arch/blackfin/include/asm/global_data.h
index eba5e93..f7aa711 100644 (file)
--- a/arch/blackfin/include/asm/global_data.h
+++ b/arch/blackfin/include/asm/global_data.h
@@ -45,6 +45,9 @@ typedef struct global_data {
        unsigned long board_type;
        unsigned long baudrate;
        unsigned long have_console;     /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        phys_size_t ram_size;           /* RAM size */
        unsigned long env_addr; /* Address  of Environment struct */
        unsigned long env_valid;        /* Checksum of Environment valid? */

diff --git a/arch/m68k/include/asm/global_data.h b/arch/m68k/include/asm/global_data.h
index fc486fd..0ba2b43 100644 (file)
--- a/arch/m68k/include/asm/global_data.h
+++ b/arch/m68k/include/asm/global_data.h
@@ -57,6 +57,9 @@ typedef       struct  global_data {
        unsigned long   env_addr;       /* Address  of Environment struct       */
        unsigned long   env_valid;      /* Checksum of Environment valid?       */
        unsigned long   have_console;   /* serial_init() was called             */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
 #if defined(CONFIG_LCD) || defined(CONFIG_VIDEO)
        unsigned long   fb_base;        /* Base addr of framebuffer memory */
 #endif

diff --git a/arch/microblaze/include/asm/global_data.h b/arch/microblaze/include/asm/global_data.h
index 557ad27..6e8537c 100644 (file)
--- a/arch/microblaze/include/asm/global_data.h
+++ b/arch/microblaze/include/asm/global_data.h
@@ -39,6 +39,9 @@ typedef       struct  global_data {
        unsigned long   flags;
        unsigned long   baudrate;
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        unsigned long   env_addr;       /* Address  of Environment struct */
        unsigned long   env_valid;      /* Checksum of Environment valid? */
        unsigned long   fb_base;        /* base address of frame buffer */

diff --git a/arch/mips/include/asm/global_data.h b/arch/mips/include/asm/global_data.h
index 271a290..b193517 100644 (file)
--- a/arch/mips/include/asm/global_data.h
+++ b/arch/mips/include/asm/global_data.h
@@ -41,6 +41,9 @@ typedef       struct  global_data {
        unsigned long   flags;
        unsigned long   baudrate;
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        phys_size_t     ram_size;       /* RAM size */
        unsigned long   reloc_off;      /* Relocation Offset */
        unsigned long   env_addr;       /* Address  of Environment struct */

diff --git a/arch/nios2/include/asm/global_data.h b/arch/nios2/include/asm/global_data.h
index 2c4a719..d9f0664 100644 (file)
--- a/arch/nios2/include/asm/global_data.h
+++ b/arch/nios2/include/asm/global_data.h
@@ -29,6 +29,9 @@ typedef       struct  global_data {
        unsigned long   baudrate;
        unsigned long   cpu_clk;        /* CPU clock in Hz!             */
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        phys_size_t     ram_size;       /* RAM size */
        unsigned long   env_addr;       /* Address  of Environment struct */
        unsigned long   env_valid;      /* Checksum of Environment valid */

diff --git a/arch/powerpc/include/asm/global_data.h b/arch/powerpc/include/asm/global_data.h
index a33ca2f..7fcaf38 100644 (file)
--- a/arch/powerpc/include/asm/global_data.h
+++ b/arch/powerpc/include/asm/global_data.h
@@ -138,6 +138,9 @@ typedef     struct  global_data {
        unsigned long   env_addr;       /* Address  of Environment struct       */
        unsigned long   env_valid;      /* Checksum of Environment valid?       */
        unsigned long   have_console;   /* serial_init() was called             */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
 #if defined(CONFIG_SYS_ALLOC_DPRAM) || defined(CONFIG_CPM2)
        unsigned int    dp_alloc_base;
        unsigned int    dp_alloc_top;

diff --git a/arch/sh/include/asm/global_data.h b/arch/sh/include/asm/global_data.h
index 0c09ba9..1b782fc 100644 (file)
--- a/arch/sh/include/asm/global_data.h
+++ b/arch/sh/include/asm/global_data.h
@@ -34,6 +34,9 @@ typedef       struct global_data
        unsigned long   baudrate;
        unsigned long   cpu_clk;        /* CPU clock in Hz! */
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        phys_size_t     ram_size;       /* RAM size */
        unsigned long   env_addr;       /* Address  of Environment struct */
        unsigned long   env_valid;      /* Checksum of Environment valid */

diff --git a/arch/sparc/include/asm/global_data.h b/arch/sparc/include/asm/global_data.h
index 9b14674..a1e4b44 100644 (file)
--- a/arch/sparc/include/asm/global_data.h
+++ b/arch/sparc/include/asm/global_data.h
@@ -53,6 +53,9 @@ typedef struct global_data {
        unsigned long env_valid;        /* Checksum of Environment valid?       */
        unsigned long have_console;     /* serial_init() was called */
 
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
 #if defined(CONFIG_LCD) || defined(CONFIG_VIDEO)
        unsigned long fb_base;  /* Base address of framebuffer memory   */
 #endif

diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
index f8a16d6..f177a4f 100644 (file)
--- a/arch/x86/include/asm/global_data.h
+++ b/arch/x86/include/asm/global_data.h
@@ -40,6 +40,9 @@ typedef       struct global_data {
        unsigned long   flags;
        unsigned long   baudrate;
        unsigned long   have_console;   /* serial_init() was called */
+#ifdef CONFIG_PRE_CONSOLE_BUFFER
+       unsigned long   precon_buf_idx; /* Pre-Console buffer index */
+#endif
        unsigned long   reloc_off;      /* Relocation Offset */
        unsigned long   load_off;       /* Load Offset */
        unsigned long   env_addr;       /* Address  of Environment struct */

diff --git a/common/console.c b/common/console.c
index b23d933..f17875e 100644 (file)
--- a/common/console.c
+++ b/common/console.c
@@ -329,6 +329,39 @@ int tstc(void)
        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 @@ void putc(const char c)
 #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 @@ void puts(const char *s)
 #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 @@ int printf(const char *fmt, ...)
        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 @@ int vprintf(const char *fmt, va_list args)
        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 @@ int console_init_f(void)
                gd->flags |= GD_FLG_SILENT;
 #endif
 
+       print_pre_console_buffer();
+
        return 0;
 }