docs: Document FW_PIC compile time option

FW_PIC=y is on by default, but the doc is missing when this was
introduced. Add some description for it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Bin Meng
2021-07-12 08:48:02 +08:00
committed by Anup Patel
parent a4555e5698
commit 2c74dc3c47

View File

@@ -69,6 +69,12 @@ parameters:
argument by the prior booting stage.
* **FW_FDT_PADDING** - Optional zero bytes padding to the embedded flattened
device tree binary file specified by **FW_FDT_PATH** option.
* **FW_PIC** - "FW_PIC=y" generates position independent executable firmware
images. OpenSBI can run at arbitrary address with appropriate alignment.
Therefore, the original relocation mechanism ("FW_PIC=n") will be skipped.
In other words, OpenSBI will directly run at the load address without any
code movement. This option requires a toolchain with PIE support, and it
is on by default.
Additionally, each firmware type as a set of type specific configuration
parameters. Detailed information for each firmware type can be found in the