ARM: imx: Enable MMU and dcache very early on i.MX8M
Enable MMU and caches very early on in the boot process on i.MX8M
in U-Boot proper. This allows board_init_f to run with icache and
dcache enabled, which saves some 700 milliseconds of boot time on
i.MX8M Plus based device.
The 'bootstage report' output is below:
Before:
```
Timer summary in microseconds (8 records):
Mark Elapsed Stage
0 0 reset
961,363 961,363 board_init_f
1,818,874 857,511 board_init_r
1,921,474 102,600 eth_common_init
2,013,702 92,228 eth_initialize
2,015,238 1,536 main_loop
Accumulated time:
32,775 dm_r
289,165 dm_f
```
After:
```
Timer summary in microseconds (8 records):
Mark Elapsed Stage
0 0 reset
989,466 989,466 board_init_f
1,179,100 189,634 board_init_r
1,281,456 102,356 eth_common_init
1,373,857 92,401 eth_initialize
1,375,396 1,539 main_loop
Accumulated time:
12,630 dm_f
32,635 dm_r
```
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
1 file changed