src/arch/riscv/opensbi.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <arch/boot.h>
   4 #include <arch/encoding.h>
   5 #include <stdint.h>
   6 #include <stddef.h>
   7
   8 #define FW_DYNAMIC_INFO_VERSION_2    2
   9 #define FW_DYNAMIC_INFO_MAGIC_VALUE  0x4942534f // "OSBI"
  10
  11 /*
  12  * structure passed to OpenSBI as 3rd argument
  13  * NOTE: This structure may need to be updated when the OpenSBI submodule is updated.
  14  */
  15 static struct __packed fw_dynamic_info {
  16         unsigned long magic;     // magic value "OSBI"
  17         unsigned long version;   // version number (2)
  18         unsigned long next_addr; // Next booting stage address (payload address)
  19         unsigned long next_mode; // Next booting stage mode (usually supervisor mode)
  20         unsigned long options;   // options for OpenSBI library
  21         unsigned long boot_hart; // usually CONFIG_RISCV_WORKING_HARTID
  22 } info;
  23
  24 void run_opensbi(const int hart_id,
  25                  const void *fdt,
  26                  const void *opensbi,
  27                  const void *payload,
  28                  const int payload_mode)
  29 {
  30         info.magic = FW_DYNAMIC_INFO_MAGIC_VALUE,
  31         info.version = FW_DYNAMIC_INFO_VERSION_2,
  32         info.next_mode = payload_mode,
  33         info.next_addr = (uintptr_t)payload,
  34         info.options = 0,
  35         info.boot_hart = CONFIG_OPENSBI_FW_DYNAMIC_BOOT_HART,
  36
  37         write_csr(mepc, opensbi); // set program counter to OpenSBI (jumped to with mret)
  38         asm volatile (
  39                 "mv  a0, %0\n\t"
  40                 "mv  a1, %1\n\t"
  41                 "mv  a2, %2\n\t"
  42                 "mret"
  43                 :
  44                 : "r"(hart_id), "r"(fdt), "r"(&info)
  45                 : "a0", "a1", "a2"
  46         );
  47 }