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/arch/sh/include/asm/global_data.h b/arch/sh/include/asm/global_data.h
index 0c09ba9..1b782fc 100644
--- a/arch/sh/include/asm/global_data.h
+++ b/arch/sh/include/asm/global_data.h
@@ -34,6 +34,9 @@
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 */