#define SYM_SIZE 0x18
#endif
+.section .data
+secondary_harts_relocation_error:
+ .ascii "Relocation of secondary harts has failed, error %d\n"
+
.section .text
.globl _start
_start:
- /* save hart id and dtb pointer */
- mv s0, a0
+#if CONFIG_IS_ENABLED(RISCV_MMODE)
+ csrr a0, CSR_MHARTID
+#endif
+
+ /*
+ * Save hart id and dtb pointer. The thread pointer register is not
+ * modified by C code. It is used by secondary_hart_loop.
+ */
+ mv tp, a0
mv s1, a1
+ /*
+ * Set the global data pointer to a known value in case we get a very
+ * early trap. The global data pointer will be set its actual value only
+ * after it has been initialized.
+ */
+ mv gp, zero
+
+ /*
+ * Set the trap handler. This must happen after initializing gp because
+ * the handler may use it.
+ */
la t0, trap_entry
csrw MODE_PREFIX(tvec), t0
- /* mask all interrupts */
+ /*
+ * Mask all interrupts. Interrupts are disabled globally (in m/sstatus)
+ * for U-Boot, but we will need to read m/sip to determine if we get an
+ * IPI
+ */
csrw MODE_PREFIX(ie), zero
- /* Enable cache */
- jal icache_enable
- jal dcache_enable
+#if CONFIG_IS_ENABLED(SMP)
+ /* check if hart is within range */
+ /* tp: hart id */
+ li t0, CONFIG_NR_CPUS
+ bge tp, t0, hart_out_of_bounds_loop
+
+ /* set xSIE bit to receive IPIs */
+#if CONFIG_IS_ENABLED(RISCV_MMODE)
+ li t0, MIE_MSIE
+#else
+ li t0, SIE_SSIE
+#endif
+ csrs MODE_PREFIX(ie), t0
+#endif
/*
* Set stackpointer in internal/ex RAM to call board_init_f
*/
call_board_init_f:
li t0, -16
+#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
+ li t1, CONFIG_SPL_STACK
+#else
li t1, CONFIG_SYS_INIT_SP_ADDR
- and sp, t1, t0 /* force 16 byte alignment */
-
-#ifdef CONFIG_DEBUG_UART
- jal debug_uart_init
#endif
+ and sp, t1, t0 /* force 16 byte alignment */
call_board_init_f_0:
mv a0, sp
jal board_init_f_alloc_reserve
+
+ /*
+ * Save global data pointer for later. We don't set it here because it
+ * is not initialized yet.
+ */
+ mv s0, a0
+
+ /* setup stack */
+#if CONFIG_IS_ENABLED(SMP)
+ /* tp: hart id */
+ slli t0, tp, CONFIG_STACK_SIZE_SHIFT
+ sub sp, a0, t0
+#else
mv sp, a0
+#endif
+
+ /* Configure proprietary settings and customized CSRs of harts */
+call_harts_early_init:
+ jal harts_early_init
- la t0, prior_stage_fdt_address
- SREG s1, 0(t0)
+#ifndef CONFIG_XIP
+ /*
+ * Pick hart to initialize global data and run U-Boot. The other harts
+ * wait for initialization to complete.
+ */
+ la t0, hart_lottery
+ li t1, 1
+ amoswap.w s2, t1, 0(t0)
+ bnez s2, wait_for_gd_init
+#else
+ /*
+ * FIXME: gp is set before it is initialized. If an XIP U-Boot ever
+ * encounters a pending IPI on boot it is liable to jump to whatever
+ * memory happens to be in ipi_data.addr on boot. It may also run into
+ * problems if it encounters an exception too early (because printf/puts
+ * accesses gd).
+ */
+ mv gp, s0
+ bnez tp, secondary_hart_loop
+#endif
jal board_init_f_init_reserve
+ SREG s1, GD_FIRMWARE_FDT_ADDR(gp)
/* save the boot hart id to global_data */
- SREG s0, GD_BOOT_HART(gp)
+ SREG tp, GD_BOOT_HART(gp)
+
+#ifndef CONFIG_XIP
+ la t0, available_harts_lock
+ amoswap.w.rl zero, zero, 0(t0)
+
+wait_for_gd_init:
+ la t0, available_harts_lock
+ li t1, 1
+1: amoswap.w.aq t1, t1, 0(t0)
+ bnez t1, 1b
+
+ /*
+ * Set the global data pointer only when gd_t has been initialized.
+ * This was already set by arch_setup_gd on the boot hart, but all other
+ * harts' global data pointers gets set here.
+ */
+ mv gp, s0
+
+ /* register available harts in the available_harts mask */
+ li t1, 1
+ sll t1, t1, tp
+ LREG t2, GD_AVAILABLE_HARTS(gp)
+ or t2, t2, t1
+ SREG t2, GD_AVAILABLE_HARTS(gp)
+
+ amoswap.w.rl zero, zero, 0(t0)
+
+ /*
+ * Continue on hart lottery winner, others branch to
+ * secondary_hart_loop.
+ */
+ bnez s2, secondary_hart_loop
+#endif
+
+ /* Enable cache */
+ jal icache_enable
+ jal dcache_enable
+
+#ifdef CONFIG_DEBUG_UART
+ jal debug_uart_init
+#endif
mv a0, zero /* a0 <-- boot_flags = 0 */
la t5, board_init_f
- jr t5 /* jump to board_init_f() */
+ jalr t5 /* jump to board_init_f() */
+
+#ifdef CONFIG_SPL_BUILD
+spl_clear_bss:
+ la t0, __bss_start
+ la t1, __bss_end
+ beq t0, t1, spl_stack_gd_setup
+
+spl_clear_bss_loop:
+ SREG zero, 0(t0)
+ addi t0, t0, REGBYTES
+ blt t0, t1, spl_clear_bss_loop
+
+spl_stack_gd_setup:
+ jal spl_relocate_stack_gd
+
+ /* skip setup if we did not relocate */
+ beqz a0, spl_call_board_init_r
+ mv s0, a0
+
+ /* setup stack on main hart */
+#if CONFIG_IS_ENABLED(SMP)
+ /* tp: hart id */
+ slli t0, tp, CONFIG_STACK_SIZE_SHIFT
+ sub sp, s0, t0
+#else
+ mv sp, s0
+#endif
+
+#if CONFIG_IS_ENABLED(SMP)
+ /* set new stack and global data pointer on secondary harts */
+spl_secondary_hart_stack_gd_setup:
+ la a0, secondary_hart_relocate
+ mv a1, s0
+ mv a2, s0
+ mv a3, zero
+ jal smp_call_function
+
+ /* hang if relocation of secondary harts has failed */
+ beqz a0, 1f
+ mv a1, a0
+ la a0, secondary_harts_relocation_error
+ jal printf
+ jal hang
+#endif
+
+ /* set new global data pointer on main hart */
+1: mv gp, s0
+
+spl_call_board_init_r:
+ mv a0, zero
+ mv a1, zero
+ jal board_init_r
+#endif
/*
- * void relocate_code (addr_sp, gd, addr_moni)
+ * void relocate_code(addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*Set up the stack
*/
stack_setup:
+#if CONFIG_IS_ENABLED(SMP)
+ /* tp: hart id */
+ slli t0, tp, CONFIG_STACK_SIZE_SHIFT
+ sub sp, s2, t0
+#else
mv sp, s2
+#endif
+
la t0, _start
sub t6, s4, t0 /* t6 <- relocation offset */
beq t0, s4, clear_bss /* skip relocation */
/*
* skip first reserved entry: address, type, addend
*/
- bne t1, t2, 7f
+ j 10f
6:
LREG t5, -(REGBYTES*2)(t1) /* t5 <-- relocation info:type */
add t5, t5, t6 /* t5 <-- location to fix up in RAM */
add t3, t3, t6 /* t3 <-- location to fix up in RAM */
SREG t5, 0(t3)
-7:
- addi t1, t1, (REGBYTES*3)
- ble t1, t2, 6b
+ j 10f
8:
la t4, __dyn_sym_start
li t5, SYM_SIZE
mul t0, t0, t5
add s5, t4, t0
+ LREG t0, -(REGBYTES)(t1) /* t0 <-- addend */
LREG t5, REGBYTES(s5)
+ add t5, t5, t0
add t5, t5, t6 /* t5 <-- location to fix up in RAM */
add t3, t3, t6 /* t3 <-- location to fix up in RAM */
SREG t5, 0(t3)
10:
addi t1, t1, (REGBYTES*3)
- ble t1, t2, 9b
+ ble t1, t2, 6b
/*
* trap update
add t0, t0, t6 /* t0 <- rel __bss_start in RAM */
la t1, __bss_end /* t1 <- rel __bss_end in FLASH */
add t1, t1, t6 /* t1 <- rel __bss_end in RAM */
- beq t0, t1, call_board_init_r
+ beq t0, t1, relocate_secondary_harts
clbss_l:
SREG zero, 0(t0) /* clear loop... */
addi t0, t0, REGBYTES
- bne t0, t1, clbss_l
+ blt t0, t1, clbss_l
+
+relocate_secondary_harts:
+#if CONFIG_IS_ENABLED(SMP)
+ /* send relocation IPI */
+ la t0, secondary_hart_relocate
+ add a0, t0, t6
+
+ /* store relocation offset */
+ mv s5, t6
+
+ mv a1, s2
+ mv a2, s3
+ mv a3, zero
+ jal smp_call_function
+
+ /* hang if relocation of secondary harts has failed */
+ beqz a0, 1f
+ mv a1, a0
+ la a0, secondary_harts_relocation_error
+ jal printf
+ jal hang
+
+ /* restore relocation offset */
+1: mv t6, s5
+#endif
/*
* We are done. Do not return, instead branch to second part of board
call_board_init_r:
jal invalidate_icache_all
jal flush_dcache_all
- la t0, board_init_r
- mv t4, t0 /* offset of board_init_r() */
- add t4, t4, t6 /* real address of board_init_r() */
+ la t0, board_init_r /* offset of board_init_r() */
+ add t4, t0, t6 /* real address of board_init_r() */
/*
* setup parameters for board_init_r
*/
* jump to it ...
*/
jr t4 /* jump to board_init_r() */
+
+#if CONFIG_IS_ENABLED(SMP)
+hart_out_of_bounds_loop:
+ /* Harts in this loop are out of bounds, increase CONFIG_NR_CPUS. */
+ wfi
+ j hart_out_of_bounds_loop
+
+/* SMP relocation entry */
+secondary_hart_relocate:
+ /* a1: new sp */
+ /* a2: new gd */
+ /* tp: hart id */
+
+ /* setup stack */
+ slli t0, tp, CONFIG_STACK_SIZE_SHIFT
+ sub sp, a1, t0
+
+ /* update global data pointer */
+ mv gp, a2
+#endif
+
+/*
+ * Interrupts are disabled globally, but they can still be read from m/sip. The
+ * wfi function will wake us up if we get an IPI, even if we do not trap.
+ */
+secondary_hart_loop:
+ wfi
+
+#if CONFIG_IS_ENABLED(SMP)
+ csrr t0, MODE_PREFIX(ip)
+#if CONFIG_IS_ENABLED(RISCV_MMODE)
+ andi t0, t0, MIE_MSIE
+#else
+ andi t0, t0, SIE_SSIE
+#endif
+ beqz t0, secondary_hart_loop
+
+ mv a0, tp
+ jal handle_ipi
+#endif
+
+ j secondary_hart_loop