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arch/riscv: Pass the bootrom-provided FDT to the payload

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The RISC-V boot protocol foresees that at every stage boundary (bootrom
to boot loader, boot loader -> OS), register a0 contains the Hart ID and
a1 contains the physical address of the Flattened Device Tree that the
stage shall use.

As a first step, pass the bootrom-provided FDT to the payload,
unmodified.

Change-Id: I468bc64a47153d564087235f1c7e2d10e3d7a658
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/23797
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
This commit is contained in:
Jonathan Neuschäfer
2018-02-16 13:36:47 +01:00
committed by Martin Roth
parent b26759d703
commit 042a8336f3
5 changed files with 78 additions and 16 deletions
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23
src/arch/riscv/boot.c
View File

@@ -15,20 +15,35 @@
#include <program_loading.h>
#include <vm.h>
#include <arch/boot.h>
#include <arch/encoding.h>
#include <rules.h>
#include <console/console.h>
/*
* A pointer to the Flattened Device Tree passed to coreboot by the boot ROM.
* Presumably this FDT is also in ROM.
*
* This pointer is only used in ramstage!
*/
const void *rom_fdt;
void arch_prog_run(struct prog *prog)
{
void (*doit)(void *) = prog_entry(prog);
void riscvpayload(const char *configstring, void *payload);
const char *config = NULL;
void riscvpayload(const void *fdt, void *payload);
if (ENV_RAMSTAGE && prog_type(prog) == PROG_PAYLOAD) {
printk(BIOS_SPEW, "Config string: '%s'\n", config);
/*
* FIXME: This is wrong and will crash. Linux can't (in early
* boot) access memory that's before its own loading address.
* We need to copy the FDT to a place where Linux can access it.
*/
const void *fdt = rom_fdt;
printk(BIOS_SPEW, "FDT is at %p\n", fdt);
printk(BIOS_SPEW, "OK, let's go\n");
riscvpayload(config, doit);
riscvpayload(fdt, doit);
}
doit(prog_entry_arg(prog));