diff options
Diffstat (limited to 'cpu/leon3/start.S')
| -rw-r--r-- | cpu/leon3/start.S | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/cpu/leon3/start.S b/cpu/leon3/start.S new file mode 100644 index 0000000..807f7e8 --- /dev/null +++ b/cpu/leon3/start.S @@ -0,0 +1,616 @@ +/* This is where the SPARC/LEON3 starts + * Copyright (C) 2007, + * Daniel Hellstrom, daniel@gaisler.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <config.h> +#include <asm/asmmacro.h> +#include <asm/winmacro.h> +#include <asm/psr.h> +#include <asm/stack.h> +#include <asm/leon.h> +#include <version.h> + +/* Entry for traps which jump to a programmer-specified trap handler. */ +#define TRAPR(H) \ + wr %g0, 0xfe0, %psr; \ + mov %g0, %tbr; \ + ba (H); \ + mov %g0, %wim; + +#define TRAP(H) \ + mov %psr, %l0; \ + ba (H); \ + nop; nop; + +#define TRAPI(ilevel) \ + mov ilevel, %l7; \ + mov %psr, %l0; \ + b _irq_entry; \ + mov %wim, %l3 + +/* Unexcpected trap will halt the processor by forcing it to error state */ +#undef BAD_TRAP +#define BAD_TRAP ta 0; nop; nop; nop; + +/* Software trap. Treat as BAD_TRAP for the time being... */ +#define SOFT_TRAP TRAP(_hwerr) + +#define PSR_INIT 0x1FC0 /* Disable traps, set s and ps */ +#define WIM_INIT 2 + +/* All traps low-level code here must end with this macro. */ +#define RESTORE_ALL b ret_trap_entry; clr %l6; + +#define WRITE_PAUSE nop;nop;nop + +WINDOWSIZE = (16 * 4) +ARGPUSHSIZE = (6 * 4) +ARGPUSH = (WINDOWSIZE + 4) +MINFRAME = (WINDOWSIZE + ARGPUSHSIZE + 4) + +/* Number of register windows */ +#ifndef CFG_SPARC_NWINDOWS +#error Must define number of SPARC register windows, default is 8 +#endif + +#define STACK_ALIGN 8 +#define SA(X) (((X)+(STACK_ALIGN-1)) & ~(STACK_ALIGN-1)) + + .section ".start", "ax" + .globl _start, start, _trap_table + .globl _irq_entry, nmi_trap + .globl _reset_reloc + +/* at address 0 + * Hardware traps + */ +start: +_start: +_trap_table: + TRAPR(_hardreset); ! 00 reset trap + BAD_TRAP; ! 01 instruction_access_exception + BAD_TRAP; ! 02 illegal_instruction + BAD_TRAP; ! 03 priveleged_instruction + BAD_TRAP; ! 04 fp_disabled + TRAP(_window_overflow); ! 05 window_overflow + TRAP(_window_underflow); ! 06 window_underflow + BAD_TRAP; ! 07 Memory Address Not Aligned + BAD_TRAP; ! 08 Floating Point Exception + BAD_TRAP; ! 09 Data Miss Exception + BAD_TRAP; ! 0a Tagged Instruction Ovrflw + BAD_TRAP; ! 0b Watchpoint Detected + BAD_TRAP; ! 0c + BAD_TRAP; ! 0d + BAD_TRAP; ! 0e + BAD_TRAP; ! 0f + BAD_TRAP; ! 10 + TRAPI(1); ! 11 IRQ level 1 + TRAPI(2); ! 12 IRQ level 2 + TRAPI(3); ! 13 IRQ level 3 + TRAPI(4); ! 14 IRQ level 4 + TRAPI(5); ! 15 IRQ level 5 + TRAPI(6); ! 16 IRQ level 6 + TRAPI(7); ! 17 IRQ level 7 + TRAPI(8); ! 18 IRQ level 8 + TRAPI(9); ! 19 IRQ level 9 + TRAPI(10); ! 1a IRQ level 10 + TRAPI(11); ! 1b IRQ level 11 + TRAPI(12); ! 1c IRQ level 12 + TRAPI(13); ! 1d IRQ level 13 + TRAPI(14); ! 1e IRQ level 14 + TRAP(_nmi_trap); ! 1f IRQ level 15 / + ! NMI (non maskable interrupt) + BAD_TRAP; ! 20 r_register_access_error + BAD_TRAP; ! 21 instruction access error + BAD_TRAP; ! 22 + BAD_TRAP; ! 23 + BAD_TRAP; ! 24 co-processor disabled + BAD_TRAP; ! 25 uniplemented FLUSH + BAD_TRAP; ! 26 + BAD_TRAP; ! 27 + BAD_TRAP; ! 28 co-processor exception + BAD_TRAP; ! 29 data access error + BAD_TRAP; ! 2a division by zero + BAD_TRAP; ! 2b data store error + BAD_TRAP; ! 2c data access MMU miss + BAD_TRAP; ! 2d + BAD_TRAP; ! 2e + BAD_TRAP; ! 2f + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 30-33 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 34-37 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 38-3b + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 3c-3f + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 40-43 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 44-47 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 48-4b + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 4c-4f + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 50-53 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 54-57 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 58-5b + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 5c-5f + + /* implementaion dependent */ + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 60-63 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 64-67 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 68-6b + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 6c-6f + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 70-73 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 74-77 + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 78-7b + BAD_TRAP; BAD_TRAP; BAD_TRAP; BAD_TRAP; ! 7c-7f + + /* Software traps, not handled */ + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 80-83 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 84-87 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 88-8b + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 8c-8f + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 90-93 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 94-97 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 98-9b + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! 9c-9f + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a0-a3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a4-a7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! a8-ab + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! ac-af + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b0-b3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b4-b7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! b8-bb + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! bc-bf + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c0-c3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c4-c7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! c8-cb + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! cc-cf + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d0-d3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d4-d7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! d8-db + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! dc-df + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e0-e3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e4-e7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! e8-eb + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! ec-ef + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f0-f3 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f4-f7 + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! f8-fb + SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; SOFT_TRAP; ! fc-ff +/* + * Version string + */ + + .data + .extern leon3_snooping_avail + .globl version_string +version_string: + .ascii U_BOOT_VERSION + .ascii " (", __DATE__, " - ", __TIME__, ")" + .ascii CONFIG_IDENT_STRING, "\0" + + .section ".text" + .align 4 + +_hardreset: +1000: + flush + + /* Enable I/D-Cache and Snooping */ + set 0x0081000f, %g2 + sta %g2, [%g0] 2 + + mov %g0, %y + clr %g1 + clr %g2 + clr %g3 + clr %g4 + clr %g5 + clr %g6 + clr %g7 + + mov %asr17, %g3 + and %g3, 0x1f, %g3 +clear_window: + mov %g0, %l0 + mov %g0, %l1 + mov %g0, %l2 + mov %g0, %l3 + mov %g0, %l4 + mov %g0, %l5 + mov %g0, %l6 + mov %g0, %l7 + mov %g0, %o0 + mov %g0, %o1 + mov %g0, %o2 + mov %g0, %o3 + mov %g0, %o4 + mov %g0, %o5 + mov %g0, %o6 + mov %g0, %o7 + subcc %g3, 1, %g3 + bge clear_window + save + +wininit: + set WIM_INIT, %g3 + mov %g3, %wim + +stackp: + set CFG_INIT_SP_OFFSET, %fp + andn %fp, 0x0f, %fp + sub %fp, 64, %sp + +cpu_init_unreloc: + call cpu_init_f + nop + +/* un relocated start address of monitor */ +#define TEXT_START _text + +/* un relocated end address of monitor */ +#define DATA_END __init_end + +reloc: + set TEXT_START,%g2 + set DATA_END,%g3 + set CFG_RELOC_MONITOR_BASE,%g4 +reloc_loop: + ldd [%g2],%l0 + ldd [%g2+8],%l2 + std %l0,[%g4] + std %l2,[%g4+8] + inc 16,%g2 + subcc %g3,%g2,%g0 + bne reloc_loop + inc 16,%g4 + + clr %l0 + clr %l1 + clr %l2 + clr %l3 + clr %g2 + +/* register g4 contain address to start + * This means that BSS must be directly after data and code segments + * + * g3 is length of bss = (__bss_end-__bss_start) + * + */ + +clr_bss: +/* clear bss area (the relocated) */ + set __bss_start,%g2 + set __bss_end,%g3 + sub %g3,%g2,%g3 + add %g3,%g4,%g3 + clr %g1 /* std %g0 uses g0 and g1 */ +/* clearing 16byte a time ==> linker script need to align to 16 byte offset */ +clr_bss_16: + std %g0,[%g4] + std %g0,[%g4+8] + inc 16,%g4 + cmp %g3,%g4 + bne clr_bss_16 + nop + +/* add offsets to GOT table */ +fixup_got: + set __got_start,%g4 + set __got_end,%g3 +/* + * new got offset = (old GOT-PTR (read with ld) - + * CFG_RELOC_MONITOR_BASE(from define) ) + + * Destination Address (from define) + */ + set CFG_RELOC_MONITOR_BASE,%g2 + set TEXT_START, %g1 + add %g4,%g2,%g4 + sub %g4,%g1,%g4 + add %g3,%g2,%g3 + sub %g3,%g1,%g3 + sub %g2,%g1,%g2 ! prepare register with (new base address) - + ! (old base address) +got_loop: + ld [%g4],%l0 ! load old GOT-PTR + add %l0,%g2,%l0 ! increase with (new base address) - + ! (old base) + st %l0,[%g4] + inc 4,%g4 + cmp %g3,%g4 + bne got_loop + nop + +prom_relocate: + set __prom_start, %g2 + set __prom_end, %g3 + set CFG_PROM_OFFSET, %g4 + +prom_relocate_loop: + ldd [%g2],%l0 + ldd [%g2+8],%l2 + std %l0,[%g4] + std %l2,[%g4+8] + inc 16,%g2 + subcc %g3,%g2,%g0 + bne prom_relocate_loop + inc 16,%g4 + +/* Trap table has been moved, lets tell CPU about + * the new trap table address + */ + + set CFG_RELOC_MONITOR_BASE, %g2 + wr %g0, %g2, %tbr + nop + nop + nop + +/* If CACHE snooping is available in hardware the + * variable leon3_snooping_avail will be set to + * 0x800000 else 0. + */ +snoop_detect: + sethi %hi(0x00800000), %o0 + lda [%g0] 2, %o1 + and %o0, %o1, %o0 + sethi %hi(leon3_snooping_avail+CFG_RELOC_MONITOR_BASE-TEXT_BASE), %o1 + st %o0, [%lo(leon3_snooping_avail+CFG_RELOC_MONITOR_BASE-TEXT_BASE)+%o1] + +/* call relocate*/ + nop +/* Call relocated init functions */ +jump: + set cpu_init_f2,%o1 + set CFG_RELOC_MONITOR_BASE,%o2 + add %o1,%o2,%o1 + sub %o1,%g1,%o1 + call %o1 + clr %o0 + + set board_init_f,%o1 + set CFG_RELOC_MONITOR_BASE,%o2 + add %o1,%o2,%o1 + sub %o1,%g1,%o1 + call %o1 + clr %o0 + +dead: ta 0 ! if call returns... + nop + +/* Interrupt handler caller, + * reg L7: interrupt number + * reg L0: psr after interrupt + * reg L1: PC + * reg L2: next PC + * reg L3: wim + */ +_irq_entry: + SAVE_ALL + + or %l0, PSR_PIL, %g2 + wr %g2, 0x0, %psr + WRITE_PAUSE + wr %g2, PSR_ET, %psr + WRITE_PAUSE + mov %l7, %o0 ! irq level + set handler_irq, %o1 + set (CFG_RELOC_MONITOR_BASE-TEXT_BASE), %o2 + add %o1, %o2, %o1 + call %o1 + add %sp, SF_REGS_SZ, %o1 ! pt_regs ptr + or %l0, PSR_PIL, %g2 ! restore PIL after handler_irq + wr %g2, PSR_ET, %psr ! keep ET up + WRITE_PAUSE + + RESTORE_ALL + +!Window overflow trap handler. + .global _window_overflow + +_window_overflow: + + mov %wim, %l3 ! Calculate next WIM + mov %g1, %l7 + srl %l3, 1, %g1 + sll %l3, (CFG_SPARC_NWINDOWS-1) , %l4 + or %l4, %g1, %g1 + + save ! Get into window to be saved. + mov %g1, %wim + nop; + nop; + nop + st %l0, [%sp + 0]; + st %l1, [%sp + 4]; + st %l2, [%sp + 8]; + st %l3, [%sp + 12]; + st %l4, [%sp + 16]; + st %l5, [%sp + 20]; + st %l6, [%sp + 24]; + st %l7, [%sp + 28]; + st %i0, [%sp + 32]; + st %i1, [%sp + 36]; + st %i2, [%sp + 40]; + st %i3, [%sp + 44]; + st %i4, [%sp + 48]; + st %i5, [%sp + 52]; + st %i6, [%sp + 56]; + st %i7, [%sp + 60]; + restore ! Go back to trap window. + mov %l7, %g1 + jmp %l1 ! Re-execute save. + rett %l2 + +/* Window underflow trap handler. */ + + .global _window_underflow + +_window_underflow: + + mov %wim, %l3 ! Calculate next WIM + sll %l3, 1, %l4 + srl %l3, (CFG_SPARC_NWINDOWS-1), %l5 + or %l5, %l4, %l5 + mov %l5, %wim + nop; nop; nop + restore ! Two restores to get into the + restore ! window to restore + ld [%sp + 0], %l0; ! Restore window from the stack + ld [%sp + 4], %l1; + ld [%sp + 8], %l2; + ld [%sp + 12], %l3; + ld [%sp + 16], %l4; + ld [%sp + 20], %l5; + ld [%sp + 24], %l6; + ld [%sp + 28], %l7; + ld [%sp + 32], %i0; + ld [%sp + 36], %i1; + ld [%sp + 40], %i2; + ld [%sp + 44], %i3; + ld [%sp + 48], %i4; + ld [%sp + 52], %i5; + ld [%sp + 56], %i6; + ld [%sp + 60], %i7; + save ! Get back to the trap window. + save + jmp %l1 ! Re-execute restore. + rett %l2 + + retl + +_nmi_trap: + nop + jmp %l1 + rett %l2 + +_hwerr: + ta 0 + nop + nop + b _hwerr ! loop infinite + nop + +/* Registers to not touch at all. */ +#define t_psr l0 /* Set by caller */ +#define t_pc l1 /* Set by caller */ +#define t_npc l2 /* Set by caller */ +#define t_wim l3 /* Set by caller */ +#define t_twinmask l4 /* Set at beginning of this entry routine. */ +#define t_kstack l5 /* Set right before pt_regs frame is built */ +#define t_retpc l6 /* If you change this, change winmacro.h header file */ +#define t_systable l7 /* Never touch this, could be the syscall table ptr. */ +#define curptr g6 /* Set after pt_regs frame is built */ + +trap_setup: +/* build a pt_regs trap frame. */ + sub %fp, (SF_REGS_SZ + PT_REGS_SZ), %t_kstack + PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2) + + /* See if we are in the trap window. */ + mov 1, %t_twinmask + sll %t_twinmask, %t_psr, %t_twinmask ! t_twinmask = (1 << psr) + andcc %t_twinmask, %t_wim, %g0 + beq 1f ! in trap window, clean up + nop + + /*------------------------------------------------- + * Spill , adjust %wim and go. + */ + srl %t_wim, 0x1, %g2 ! begin computation of new %wim + + set (CFG_SPARC_NWINDOWS-1), %g3 !NWINDOWS-1 + + sll %t_wim, %g3, %t_wim ! NWINDOWS-1 + or %t_wim, %g2, %g2 + and %g2, 0xff, %g2 + + save %g0, %g0, %g0 ! get in window to be saved + + /* Set new %wim value */ + wr %g2, 0x0, %wim + + /* Save the kernel window onto the corresponding stack. */ + RW_STORE(sp) + + restore %g0, %g0, %g0 + /*-------------------------------------------------*/ + +1: + /* Trap from kernel with a window available. + * Just do it... + */ + jmpl %t_retpc + 0x8, %g0 ! return to caller + mov %t_kstack, %sp ! jump onto new stack + +#define twin_tmp1 l4 +#define glob_tmp g4 +#define curptr g6 +ret_trap_entry: + wr %t_psr, 0x0, %psr ! enable nesting again, clear ET + + /* Will the rett land us in the invalid window? */ + mov 2, %g1 + sll %g1, %t_psr, %g1 + + set CFG_SPARC_NWINDOWS, %g2 !NWINDOWS + + srl %g1, %g2, %g2 + or %g1, %g2, %g1 + rd %wim, %g2 + andcc %g2, %g1, %g0 + be 1f ! Nope, just return from the trap + sll %g2, 0x1, %g1 + + /* We have to grab a window before returning. */ + set (CFG_SPARC_NWINDOWS-1), %g3 !NWINDOWS-1 + + srl %g2, %g3, %g2 + or %g1, %g2, %g1 + and %g1, 0xff, %g1 + + wr %g1, 0x0, %wim + + /* Grrr, make sure we load from the right %sp... */ + PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1) + + restore %g0, %g0, %g0 + RW_LOAD(sp) + b 2f + save %g0, %g0, %g0 + + /* Reload the entire frame in case this is from a + * kernel system call or whatever... + */ +1: + PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1) +2: + wr %t_psr, 0x0, %psr + nop; + nop; + nop + + jmp %t_pc + rett %t_npc + +/* This is called from relocated C-code. + * It resets the system by jumping to _start + */ +_reset_reloc: + set start, %l0 + call %l0 + nop |