[U-Boot] Loop Variable through to user space
Hi all,
during the execution of th MLO I create a variable, whose value I want to make accessible to user space applications in Android. How can this be achieved?
One way would be to write the contents of the variable to external memory and let it read by the user space process. However, I would need to make sure that during boot no other process is overwriting the address.
Do you know of any other ways?
Best, André
Hello André,
On Tue, 03 Feb 2015 13:57:28 +0100, André Schaller an.schall@googlemail.com wrote:
Hi all,
during the execution of th MLO I create a variable, whose value I want to make accessible to user space applications in Android. How can this be achieved?
One way would be to write the contents of the variable to external memory and let it read by the user space process. However, I would need to make sure that during boot no other process is overwriting the address.
Do you know of any other ways?
Kind of a hack, but maybe you could pass the value somehow through the kernel boot parameters? I assume that a meaningless parameter does not affect the kernel but can still be parsed from /proc/cmdline.
Best, André
Amicalement,
Hello Albert,
thanks for the information. Do you mean to pass the value using an environment variable to the boot parameter? How would I approach to set up an environment variable in the SPL? Wouldn't it increase the memory footprint such that the SPL wouldn't fit into SRAM anymore?
Best, André
Am 03.02.15 um 23:27 schrieb Albert ARIBAUD:
Hello André,
On Tue, 03 Feb 2015 13:57:28 +0100, André Schaller an.schall@googlemail.com wrote:
Hi all,
during the execution of th MLO I create a variable, whose value I want to make accessible to user space applications in Android. How can this be achieved?
One way would be to write the contents of the variable to external memory and let it read by the user space process. However, I would need to make sure that during boot no other process is overwriting the address.
Do you know of any other ways?
Kind of a hack, but maybe you could pass the value somehow through the kernel boot parameters? I assume that a meaningless parameter does not affect the kernel but can still be parsed from /proc/cmdline.
Best, André
Amicalement,
Hi,
On 3 February 2015 at 05:57, André Schaller an.schall@googlemail.com wrote:
Hi all,
during the execution of th MLO I create a variable, whose value I want to make accessible to user space applications in Android. How can this be achieved?
One way would be to write the contents of the variable to external memory and let it read by the user space process. However, I would need to make sure that during boot no other process is overwriting the address.
Do you know of any other ways?
You could add it to the device tree in ft_board_setup() or ft_system_setup().
Regards, Simon
participants (3)
-
Albert ARIBAUD -
André Schaller -
Simon Glass