oh, wait, i think i just answered some of my questions based on this
snippet from common/env_nvram.c:
/*
* Initialize Environment use
*
* We are still running from ROM, so data use is limited
*/
int env_init(void)
{
#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
ulong crc;
uchar data[ENV_SIZE];
nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
if (crc32(0, data, ENV_SIZE) == crc) {
gd->env_addr = (ulong)CONFIG_ENV_ADDR + sizeof(long);
#else
if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
gd->env_addr = (ulong)&env_ptr->data;
#endif
gd->env_valid = 1;
} else {
gd->env_addr = (ulong)&default_environment[0];
gd->env_valid = 0;
}
return 0;
}
so if there is a valid environment at the address specified by the
board header file, it's used, otherwise fall back to
default_environment[]. i had suspected it was something like that, i
just hadn't found the code yet.
is this written up somewhere?
rday
p.s. how does the default environment get to the CONFIG_ENV_ADDR
defined in the board header file? is that done automatically when
u-boot starts to run and notices that there is no valid environment
info at that address, and therefore copies it for you?
i will keep reading the source.
--
========================================================================
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
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