Add a mechanism for early SoC initialization for platforms that need
additional hardware initialization not possible through the regular
device tree and drivers mechanism. With this, a SoC specific
initialization function can be called very early, before DTB parsing
is done by parse_dtb() in Linux RISC-V kernel setup code.
This can be very useful for early hardware initialization for No-MMU
kernels booted directly in M-mode because it is quite likely that no
other booting stage exist prior to the No-MMU kernel.
Example use of a SoC early initialization is as follows:
static void vendor_abc_early_init(const void *fdt)
{
/*
* some early init code here that can use simple matches
* against the flat device tree file.
*/
}
SOC_EARLY_INIT_DECLARE("vendor,abc", abc_early_init);
This early initialization function is executed only if the flat device
tree for the board has a 'compatible = "vendor,abc"' entry;
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Damien Le Moal