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crt0 now takes HW info from SYSINFO module

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stnolting 2020-07-17 23:40:50 +02:00
parent d098e1d6b1
commit 8430617464
1 changed files with 9 additions and 18 deletions
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27
sw/common/crt0.S
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@ -42,16 +42,12 @@
.global _start
// custom CSRs
.set CSR_MISPACEBASE, 0xfc4 // CUSTOM (r/-): Base address of instruction memory space (via MEM_ISPACE_BASE generic) */
.set CSR_MDSPACEBASE, 0xfc5 // CUSTOM (r/-): Base address of data memory space (via MEM_DSPACE_BASE generic) */
.set CSR_MISPACESIZE, 0xfc6 // CUSTOM (r/-): Total size of instruction memory space in byte (via MEM_ISPACE_SIZE generic) */
.set CSR_MDSPACESIZE, 0xfc7 // CUSTOM (r/-): Total size of data memory space in byte (via MEM_DSPACE_SIZE generic) */
// IO region
.set IO_BEGIN, 0xFFFFFF80 // start of processor-internal IO region
.set MTIMECMP_LO, 0xFFFFFF98
.set MTIMECMP_HI, 0xFFFFFF9C
.set IO_BEGIN, 0xFFFFFF80 // start of processor-internal IO region
// SYSINFO
.set SYSINFO_DSPACE_BASE, 0xFFFFFFF4
.set SYSINFO_DSPACE_SIZE, 0xFFFFFFFC
_start:
@ -114,8 +110,8 @@ __crt0_tests:
// Setup stack pointer
// *********************************************************
__crt0_stack_pointer_init:
csrr x11, CSR_MDSPACEBASE // data memory space base address
csrr x12, CSR_MDSPACESIZE // data memory space size
lw x11, SYSINFO_DSPACE_BASE(zero) // data memory space base address
lw x12, SYSINFO_DSPACE_SIZE(zero) // data memory space size
add sp, x11, x12
addi sp, sp, -4 // stack pointer = last entry
addi fp, sp, 0 // frame pointer = stack pointer
@ -138,7 +134,7 @@ __crt0_neorv32_rte_init:
la x11, __crt0_neorv32_rte
csrw mtvec, x11 // set address of first-level exception handler
csrr x11, CSR_MDSPACEBASE // data memory space base address
lw x11, SYSINFO_DSPACE_BASE(zero) // data memory space base address
la x12, __crt0_neorv32_rte_dummy_hanlder
li x13, 2*16 // number of entries (16xEXC, 16xIRQ)
@ -162,11 +158,6 @@ __crt0_reset_io_loop:
addi x11, x11, 4
bne zero, x11, __crt0_reset_io_loop
// set mtime_compare to MAX (to prevent an IRQ)
li x11, -1
sw x11, MTIMECMP_LO(zero)
sw x11, MTIMECMP_HI(zero)
// *********************************************************
// Clear .bss section (byte-wise)
@ -280,7 +271,7 @@ __crt0_neorv32_rte:
andi t1, t0, 0x0f // isolate cause ID
slli t1, t1, 2 // make address offset
csrr ra, CSR_MDSPACEBASE // data memory space base address
lw ra, SYSINFO_DSPACE_BASE(zero) // data memory space base address
add t1, t1, ra // get vetor table entry address (EXC vectors)
csrr ra, mepc // get return address