Hi Marek,
On Wed, 27 Oct 2021 at 21:28, Marek Behún kabel@kernel.org wrote:
From: Marek Behún marek.behun@nic.cz
The default_environment[] buffer is built at compile time, but sometimes it makes sense for some default environment variables to be determined at runtime, for example:
- one board code may support different boards, and needs that fdtfile, board, board_name are set appropriately when command env default -a is executed
- some boards may want to prohibit the env default -a command to remove device MAC addresses stored in ethaddr, ethNaddr. This is the case for the ESPRESSObin board code, for example, where currently the board_late_init() function rewrites the default environment array to achieve this.
Add a new board specific function,
const char *board_special_default_env(unsigned i, const char **name);
which returns the value of i-th board special default environemnt variable, while storing it's name to *name.
Add default weak implementation of this functions returning NULL.
Add code to default environemnt handlers in env/common.c, which iterate these special board default environment variables and get it's values in precedence to values in the default_environment[] buffer.
Signed-off-by: Marek Behún marek.behun@nic.cz
env/common.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 96 insertions(+), 3 deletions(-)
What do you think about using a sysinfo driver for this? There are already a lot of weak functions in U-Boot.
Regards, Simon