Hi all,

I'm working with the u-boot-2009-08.tar.bz2 and find some code I am not very clear. My puzzle is about the extern array "environment[]" which declared in "env_flash.c" as an array composed by unsigned char. However, it is defined as a env_t struct in the "env_embedded.c". So the declaration conflicts with definition, but it can be compiled normally, does any one tell me why? Thanks.

Here is the code in ./common/env_flash.c and ./common/env_embedded.c

****************************************************************************** /* In file ./common/env_flash.c */

#ifdef ENV_IS_EMBEDDED

extern uchar environment[]; env_t *env_ptr = (env_t *)(&environment[0]);

#ifdef CMD_SAVEENV /* static env_t *flash_addr = (env_t *)(&environment[0]);-broken on ARM-wd-*/ static env_t *flash_addr = (env_t *)CONFIG_ENV_ADDR; #endif

#else /* ! ENV_IS_EMBEDDED */

env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR; #ifdef CMD_SAVEENV static env_t *flash_addr = (env_t *)CONFIG_ENV_ADDR; #endif

****************************************************************************** /* In file ./common/env_embedded.c */

#ifdef ENV_IS_EMBEDDED

...

env_t environment __PPCENV__ = { ENV_CRC, /* CRC Sum */ #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 1, /* Flags: valid */ #endif { #if defined(CONFIG_BOOTARGS) "bootargs=" CONFIG_BOOTARGS "\0" #endif #if defined(CONFIG_BOOTCOMMAND) "bootcmd=" CONFIG_BOOTCOMMAND "\0" #endif

.....

};

...

#endif ******************************************************************************