[incubator-nuttx] 04/09: mpfs_head.S: Support for booting on different harts and from eNVM

[xi...@apache.org]

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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git

commit c5b11f42b6bc8fe589bac037df37e3c965582a46
Author: Jukka Laitinen <ju...@ssrc.tii.ae>
AuthorDate: Tue May 11 00:16:43 2021 +0300

    mpfs_head.S: Support for booting on different harts and from eNVM
    
    - Fix the FPU enabling code
    - If booting from eNVM, all harts start booting. With CONFIG_MPFS_BOOTLOADER,
      one can allow just one hart booting and rest are stuck in wfi.
    - Check that mtvec is actually updated before continuing the boot
    - Create 5 IRQ stacks, one for each hart
    
    Signed-off-by: Jukka Laitinen <ju...@ssrc.tii.ae>
---
 arch/risc-v/src/mpfs/mpfs_head.S | 41 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/risc-v/src/mpfs/mpfs_head.S b/arch/risc-v/src/mpfs/mpfs_head.S
index d403c02..5995066 100755
--- a/arch/risc-v/src/mpfs/mpfs_head.S
+++ b/arch/risc-v/src/mpfs/mpfs_head.S
@@ -130,6 +130,47 @@ __start_mpfs:
 
 .skip_e51:
 
+#ifdef CONFIG_MPFS_BOOTLOADER
+
+  /* Set all but the boot hart into wfi */
+
+  li a1, CONFIG_MPFS_BOOT_HART
+  beq a0, a1, .continue_boot
+
+  /* Enable IRQ_M_SOFT */
+
+  li a2, (1U << 3)
+  csrw mie, a2     /* Set MSIE bit to receive IPI */
+
+  /* flush the instruction cache */
+  fence.i
+
+.wait_boot:
+  wfi
+
+  /* Only start if MIP_MSIP is set. Breakpoints in the debugger (halt)
+   * will wakeup wfi, so we will check again that we actually got the soft
+   * interrupt
+   */
+
+  csrr a2, mip
+  andi a2, a2, (1U << 3) /* MIP_MSIP */
+  beqz a2, .wait_boot
+
+  /* Disable and clear all interrupts (the sw interrupt) */
+  li a2, 0x00000008      /* MSTATUS_MIE */
+  csrc mstatus, a2
+  csrw mie, zero
+  csrw mip, zero
+
+  /* Jump to app (TODO: remove fixed address) */
+  li a1, 0x80000000
+  jr a1
+
+.continue_boot:
+
+#endif
+
   /* Set stack pointer to the idle thread stack */
 
   la   sp, MPFS_IDLESTACK_TOP