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author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-04-20 10:19:28 +0200 |
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committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-04-20 13:08:36 +0200 |
commit | fbcd7c8fa65eb695e96a62ea1c1ac7a024fa9dfc (patch) | |
tree | a17e285cf22cd49cd42e8b3ad562febc3987d566 /bsps/mips/hurricane | |
parent | bsps: Move console drivers to bsps (diff) | |
download | rtems-fbcd7c8fa65eb695e96a62ea1c1ac7a024fa9dfc.tar.bz2 |
bsps: Move start files to bsps
This patch is a part of the BSP source reorganization.
Update #3285.
Diffstat (limited to 'bsps/mips/hurricane')
-rw-r--r-- | bsps/mips/hurricane/start/start.S | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/bsps/mips/hurricane/start/start.S b/bsps/mips/hurricane/start/start.S new file mode 100644 index 0000000000..e3d97cd167 --- /dev/null +++ b/bsps/mips/hurricane/start/start.S @@ -0,0 +1,339 @@ +/* + +Based upon IDT provided code with the following release: + +This source code has been made available to you by IDT on an AS-IS +basis. Anyone receiving this source is licensed under IDT copyrights +to use it in any way he or she deems fit, including copying it, +modifying it, compiling it, and redistributing it either with or +without modifications. No license under IDT patents or patent +applications is to be implied by the copyright license. + +Any user of this software should understand that IDT cannot provide +technical support for this software and will not be responsible for +any consequences resulting from the use of this software. + +Any person who transfers this source code or any derivative work must +include the IDT copyright notice, this paragraph, and the preceeding +two paragraphs in the transferred software. + +COPYRIGHT IDT CORPORATION 1996 +LICENSED MATERIAL - PROGRAM PROPERTY OF IDT +*/ + +/************************************************************************* +** +** Copyright 1991-95 Integrated Device Technology, Inc. +** All Rights Reserved +** +**************************************************************************/ + + +#include <rtems/mips/iregdef.h> +#include <rtems/mips/idtcpu.h> +#include <rtems/asm.h> + +#include <bsp.h> + +#if 0 + .extern _fdata,4 /* this is defined by the linker */ + .extern _edata,4 /* this is defined by the linker */ + .extern _idata,4 /* this is defined by the linker */ +#endif + .extern _fbss,4 /* this is defined by the linker */ + .extern end,4 /* this is defined by the linker */ + + .lcomm sim_mem_cfg_struct,12 + + .text + +/* For the V3 Eval board, we can safely assume that we have + at least 16 megabytes of RAM */ +#define HARD_CODED_MEM_SIZE 0x1000000 + +#define TMP_STKSIZE 1024 + +/* +** P_STACKSIZE is the size of the Prom Stack. +** the prom stack grows downward +*/ +#define P_STACKSIZE 0x2000 /* sets stack size to 8k */ + +/************************************************************************** +** +** start - Typical standalone start up code required for R3000/R4000 +** +** +** 1) Initialize the STATUS Register +** a) Clear parity error bit +** b) Set co_processor 1 usable bit ON +** c) Clear all IntMask Enables +** d) Set kernel/disabled mode +** 2) Initialize Cause Register +** a) clear software interrupt bits +** 3) Determine FPU installed or not +** if not, clear CoProcessor 1 usable bit +** 4) Clear bss area +** 5) MUST allocate temporary stack until memory size determined +** It MUST be uncached to prevent overwriting when caches are cleared +** 6) Install exception handlers +** 7) Determine memory and cache sizes +** 8) Establish permanent stack (cached or uncached as defined by bss) +** 9) Flush Instruction and Data caches +** 10) If there is a Translation Lookaside Buffer, Clear the TLB +** 11) Execute initialization code if the IDT/c library is to be used +** +** 12) Jump to user's "main()" (boot_card() for RTEMS) +** 13) Jump to promexit +** +** IDT/C 5.x defines _R3000, IDT/C 6.x defines _R4000 internally. +** This is used to mark code specific to R3xxx or R4xxx processors. +** IDT/C 6.x defines __mips to be the ISA level for which we're +** generating code. This is used to make sure the stack etc. is +** double word aligned, when using -mips3 (default) or -mips2, +** when compiling with IDT/C6.x +** +***************************************************************************/ + +FRAME(start,sp,0,ra) + + .set noreorder +#if __mips_fpr == 64 + li v0,SR_CU1|SR_FR|SR_DE /* initally clear ERL, enable FPU with 64 bit regs, disable cache errors */ +#else + li v0,SR_CU1|SR_DE /* initally clear ERL, enable FPU with 32 bit regs, disable cache errors */ +#endif + + mtc0 v0,C0_SR /* clr IntMsks/ kernel/disabled mode */ + nop + mtc0 zero,C0_CAUSE /* clear software interrupts */ + nop + + la t0,0xBE200000 /* on Hurricane board, enable interrupt output signal from UART ch. B */ + li t1,0x8 /* UART INT B signal is left tri-state'd after reset, this results in processor interrupt signal being driven active low */ + sw t1,0x10(t0) + + li v0,CFG_C_NONCOHERENT # initialise default cache mode + mtc0 v0,C0_CONFIG + +/* +** check to see if an fpu is really plugged in +*/ + li t3,0xaaaa5555 /* put a's and 5's in t3 */ + mtc1 t3,fp0 /* try to write them into fp0 */ + mtc1 zero,fp1 /* try to write zero in fp */ + mfc1 t0,fp0 + mfc1 t1,fp1 + nop + bne t0,t3,1f /* branch if no match */ + nop + bne t1,zero,1f /* double check for positive id */ + nop + /* We have a FPU. clear fcsr */ + ctc1 zero, fcr31 + j 2f /* status register already correct */ + nop +1: + li v0,SR_DE /* clear ERL and disable FPA */ + + mtc0 v0, C0_SR /* reset status register */ +2: + la gp, _gp + +#if 0 + /* Initialize data sections from "rom" copy */ + la t0,_idata /* address of initialization data (copy of data sections placed in ROM) */ + la t1,_fdata /* start of initialized data section */ + la t2,_edata /* end of initialized data section */ +3: + lw t3,0(t0) + sw t3,0(t1) + addiu t1,t1,4 + bne t1,t2,3b + addiu t0,t0,4 +#endif + + /* clear bss before using it */ + la v0,_fbss /* start of bss */ + la v1,end /* end of bss */ +4: sw zero,0(v0) + bltu v0,v1,4b + add v0,4 + + +/************************************************************************ +** +** Temporary Stack - needed to handle stack saves until +** memory size is determined and permanent stack set +** +** MUST be uncached to avoid confusion at cache +** switching during memory sizing +** +*************************************************************************/ + /* For MIPS 3, we need to be sure that the stack is aligned on a + * double word boundary. + */ + andi t0, v0, 0x7 + beqz t0, 11f /* Last three bits Zero, already aligned */ + nop + add v0, 4 +11: + + or v0, K1BASE /* switch to uncached */ + add v1, v0, TMP_STKSIZE /* end of bss + length of tmp stack */ + sub v1, v1, (4*4) /* overhead */ + move sp, v1 /* set sp to top of stack */ +4: sw zero, 0(v0) + bltu v0, v1, 4b /* clear out temp stack */ + add v0, 4 + +/* jal init_exc_vecs */ /* install exception handlers */ +/* nop */ /* MUST do before memory probes */ + + /* Force processor into uncached space during memory/cache probes */ + la v0, 5f + li v1, K1BASE + or v0, v1 + j v0 + nop +5: + + li a0, HARD_CODED_MEM_SIZE /* Set memory size global */ + jal set_memory_size + nop + + la a0, sim_mem_cfg_struct + jal get_mem_conf /* Make call to get mem size */ + nop + la a0, sim_mem_cfg_struct + lw a0, 0(a0) /* Get memory size from struct */ + + jal config_cache /* determine size of D & I caches */ + nop + + move v0, a0 /* mem_size */ + + /* For MIPS 3, we need to be sure that the stack (and hence v0 + * here) is aligned on a double word boundary. + */ + andi t0, v0, 0x7 + beqz t0, 12f /* Last three bits Zero, already aligned */ + nop + subu v0, 4 /* mem_size was not aligned on doubleword bdry????*/ +12: + + + +/************************************************************************** +** +** Permanent Stack - now know top of memory, put permanent stack there +** +***************************************************************************/ + + la t2, _fbss /* cache mode as linked */ + and t2, 0xF0000000 /* isolate segment */ + la t1, 6f + j t1 /* back to original cache mode */ + nop +6: + or v0, t2 /* stack back to original cache mode */ + addiu v0,v0,-16 /* overhead */ + move sp, v0 /* now replace count w top of memory */ + move v1, v0 + subu v1, P_STACKSIZE /* clear requested stack size */ + +7: sw zero, 0(v1) /* clear P_STACKSIZE stack */ + bltu v1,v0,7b + add v1, 4 + .set reorder + +/* FIX THIS - This corrupts memory spaces */ +/* jal flush_cache_nowrite */ /* flush Data & Instruction caches */ + +/* jal mon_flush_cache */ + +/************************************************************************** +** +** If this chip supports a Translation Lookaside Buffer, clear it +** +***************************************************************************/ + + .set noreorder + mfc0 t1, C0_SR /* look at Status Register */ + nop + .set reorder + + jal init_tlb /* clear the tlb */ + +/* Force processor into cached instruction space for rest of initialization */ +#if 0 + la t0, 1f + li t1, K0BASE /* force into cached space */ + or t0, t1 + j t0 + nop +1: +#endif + +/************************************************************************ +** +** Initialization required if using IDT/c or libc.a, standard C Lib +** +** can SKIP if not necessary for application +** +************************************************************************/ +8: + +/* FIX THIS - Need the pmon equivalent + jal idtsim_init_sbrk + jal idtsim_init_file +*/ + +/*********************** END I/O initialization **********************/ + + + move a0,zero /* Set command line passed to main */ + jal boot_card + nop + + # jump to the "exit" routine + jal idtsim__exit + move a0,v0 # pass through the exit code + + + # FIX THIS - Need the pmon equivalent + # jal idtsim_promexit + +1: + beq zero,zero,1b + nop + +ENDFRAME(start) + +/* + * _sys_exit -- Exit from the application. Normally we cause a user trap + * to return to the ROM monitor for another run. NOTE: This is + * the only other routine we provide in the crt0.o object, since + * it may be tied to the "_start" routine. It also allows + * executables that contain a complete world to be linked with + * just the crt0.o object. + */ +FRAME(_sys_exit,sp,0,ra) + + break 1023 + nop +13: + b 13b # but loop back just in-case + nop + +ENDFRAME(_sys_exit) + + + + .globl __sizemem + .ent __sizemem +__sizemem: + li v0,HARD_CODED_MEM_SIZE + j ra + nop + .end __sizemem |