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riscv: use mret to invoke M-mode payload and disable interrupts 

Fixes a logic error that sets MPIE, but didn't use mret to return to the payload.
This left MIE set to an undefined value.

Now all modes are handled the same way:
- Trap vector base address point to the payload
- Disable Interrupt
- Return to payload using mret

TEST=Run an M-mode payload

Change-Id: Iaab595f916949c57104ec00f8b06ea047fe76bba
Signed-off-by: Xiang Wang <wxjstz@126.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33462
Reviewed-by: Philipp Hug <philipp@hug.cx>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Xiang Wang 2019-06-14 16:45:54 +08:00 committed by Patrick Rudolph
parent 3280aa7df2
commit b1e6654d86
1 changed files with 20 additions and 5 deletions
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25
src/arch/riscv/payload.c
View File

@ -19,23 +19,38 @@
#include <arch/boot.h>
#include <arch/encoding.h>
#include <console/console.h>
#include <vm.h>
void run_payload(struct prog *prog, void *fdt, int payload_mode)
{
void (*doit)(int hart_id, void *fdt) = prog_entry(prog);
int hart_id = read_csr(mhartid);
uintptr_t status = read_csr(mstatus);
status &= ~MSTATUS_MPIE;
status &= ~MSTATUS_MPP;
status = INSERT_FIELD(status, MSTATUS_MPIE, 0);
switch (payload_mode) {
case RISCV_PAYLOAD_MODE_U:
status = INSERT_FIELD(status, MSTATUS_MPP, PRV_U);
/* Trap vector base address point to the payload */
write_csr(utvec, doit);
/* disable U-Mode interrupt */
write_csr(uie, 0);
break;
case RISCV_PAYLOAD_MODE_S:
status |= MSTATUS_SPP;
status = INSERT_FIELD(status, MSTATUS_MPP, PRV_S);
/* Trap vector base address point to the payload */
write_csr(stvec, doit);
/* disable S-Mode interrupt */
write_csr(sie, 0);
/* disable MMU */
write_csr(satp, 0);
break;
case RISCV_PAYLOAD_MODE_M:
doit(hart_id, fdt);
return;
status = INSERT_FIELD(status, MSTATUS_MPP, PRV_M);
/* Trap vector base address point to the payload */
write_csr(mtvec, doit);
/* disable M-Mode interrupt */
write_csr(mie, 0);
break;
default:
die("wrong privilege level for payload");
break;