From 9558b48af006a34d3ab7f0bd13a76b97acd45e47 Mon Sep 17 00:00:00 2001 From: Graeme Russ Date: Thu, 1 Sep 2011 00:48:27 +0000 Subject: 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. --- README | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'README') diff --git a/README b/README index 91b6695cf9..dfc7ada61e 100644 --- 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. -- cgit v1.2.3