linux/arch/blackfin/mach-bf533/head.S
Mike Frysinger 5079df993c Blackfin arch: document why we have to touch the UART peripheral in our boot up code
Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 09:50:22 -07:00

734 lines
14 KiB
ArmAsm

/*
* File: arch/blackfin/mach-bf533/head.S
* Based on:
* Author: Jeff Dionne <jeff@uclinux.org> COPYRIGHT 1998 D. Jeff Dionne
*
* Created: 1998
* Description: bf533 startup file
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* 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, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/linkage.h>
#include <asm/blackfin.h>
#if CONFIG_BFIN_KERNEL_CLOCK
#include <asm/mach/mem_init.h>
#endif
#if CONFIG_DEBUG_KERNEL_START
#include <asm/mach-common/def_LPBlackfin.h>
#endif
.global __rambase
.global __ramstart
.global __ramend
.extern ___bss_stop
.extern ___bss_start
.extern _bf53x_relocate_l1_mem
#define INITIAL_STACK 0xFFB01000
.text
ENTRY(__start)
ENTRY(__stext)
/* R0: argument of command line string, passed from uboot, save it */
R7 = R0;
/* Set the SYSCFG register */
R0 = 0x36;
/*Enable Cycle Counter and Nesting Of Interrupts(3rd Bit)*/
SYSCFG = R0;
R0 = 0;
/*Clear Out All the data and pointer Registers*/
R1 = R0;
R2 = R0;
R3 = R0;
R4 = R0;
R5 = R0;
R6 = R0;
P0 = R0;
P1 = R0;
P2 = R0;
P3 = R0;
P4 = R0;
P5 = R0;
LC0 = r0;
LC1 = r0;
L0 = r0;
L1 = r0;
L2 = r0;
L3 = r0;
/* Clear Out All the DAG Registers*/
B0 = r0;
B1 = r0;
B2 = r0;
B3 = r0;
I0 = r0;
I1 = r0;
I2 = r0;
I3 = r0;
M0 = r0;
M1 = r0;
M2 = r0;
M3 = r0;
#if CONFIG_DEBUG_KERNEL_START
/*
* Set up a temporary Event Vector Table, so if something bad happens before
* the kernel is fully started, it doesn't vector off into the bootloaders
* table
*/
P0.l = lo(EVT2);
P0.h = hi(EVT2);
P1.l = lo(EVT15);
P1.h = hi(EVT15);
P2.l = debug_kernel_start_trap;
P2.h = debug_kernel_start_trap;
RTS = P2;
RTI = P2;
RTX = P2;
RTN = P2;
RTE = P2;
.Lfill_temp_vector_table:
[P0++] = P2; /* Core Event Vector Table */
CC = P0 == P1;
if !CC JUMP .Lfill_temp_vector_table
P0 = r0;
P1 = r0;
P2 = r0;
#endif
p0.h = hi(FIO_MASKA_C);
p0.l = lo(FIO_MASKA_C);
r0 = 0xFFFF(Z);
w[p0] = r0.L; /* Disable all interrupts */
ssync;
p0.h = hi(FIO_MASKB_C);
p0.l = lo(FIO_MASKB_C);
r0 = 0xFFFF(Z);
w[p0] = r0.L; /* Disable all interrupts */
ssync;
/* Turn off the icache */
p0.l = (IMEM_CONTROL & 0xFFFF);
p0.h = (IMEM_CONTROL >> 16);
R1 = [p0];
R0 = ~ENICPLB;
R0 = R0 & R1;
/* Anomaly 05000125 */
#ifdef ANOMALY_05000125
CLI R2;
SSYNC;
#endif
[p0] = R0;
SSYNC;
#ifdef ANOMALY_05000125
STI R2;
#endif
/* Turn off the dcache */
p0.l = (DMEM_CONTROL & 0xFFFF);
p0.h = (DMEM_CONTROL >> 16);
R1 = [p0];
R0 = ~ENDCPLB;
R0 = R0 & R1;
/* Anomaly 05000125 */
#ifdef ANOMALY_05000125
CLI R2;
SSYNC;
#endif
[p0] = R0;
SSYNC;
#ifdef ANOMALY_05000125
STI R2;
#endif
/* Initialise UART - when booting from u-boot, the UART is not disabled
* so if we dont initalize here, our serial console gets hosed */
p0.h = hi(UART_LCR);
p0.l = lo(UART_LCR);
r0 = 0x0(Z);
w[p0] = r0.L; /* To enable DLL writes */
ssync;
p0.h = hi(UART_DLL);
p0.l = lo(UART_DLL);
r0 = 0x0(Z);
w[p0] = r0.L;
ssync;
p0.h = hi(UART_DLH);
p0.l = lo(UART_DLH);
r0 = 0x00(Z);
w[p0] = r0.L;
ssync;
p0.h = hi(UART_GCTL);
p0.l = lo(UART_GCTL);
r0 = 0x0(Z);
w[p0] = r0.L; /* To enable UART clock */
ssync;
/* Initialize stack pointer */
sp.l = lo(INITIAL_STACK);
sp.h = hi(INITIAL_STACK);
fp = sp;
usp = sp;
/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
call _bf53x_relocate_l1_mem;
#if CONFIG_BFIN_KERNEL_CLOCK
call _start_dma_code;
#endif
/* Code for initializing Async memory banks */
p2.h = hi(EBIU_AMBCTL1);
p2.l = lo(EBIU_AMBCTL1);
r0.h = hi(AMBCTL1VAL);
r0.l = lo(AMBCTL1VAL);
[p2] = r0;
ssync;
p2.h = hi(EBIU_AMBCTL0);
p2.l = lo(EBIU_AMBCTL0);
r0.h = hi(AMBCTL0VAL);
r0.l = lo(AMBCTL0VAL);
[p2] = r0;
ssync;
p2.h = hi(EBIU_AMGCTL);
p2.l = lo(EBIU_AMGCTL);
r0 = AMGCTLVAL;
w[p2] = r0;
ssync;
/* This section keeps the processor in supervisor mode
* during kernel boot. Switches to user mode at end of boot.
* See page 3-9 of Hardware Reference manual for documentation.
*/
/* EVT15 = _real_start */
p0.l = lo(EVT15);
p0.h = hi(EVT15);
p1.l = _real_start;
p1.h = _real_start;
[p0] = p1;
csync;
p0.l = lo(IMASK);
p0.h = hi(IMASK);
p1.l = IMASK_IVG15;
p1.h = 0x0;
[p0] = p1;
csync;
raise 15;
p0.l = .LWAIT_HERE;
p0.h = .LWAIT_HERE;
reti = p0;
#if defined(ANOMALY_05000281)
nop; nop; nop;
#endif
rti;
.LWAIT_HERE:
jump .LWAIT_HERE;
ENTRY(_real_start)
[ -- sp ] = reti;
p0.l = lo(WDOG_CTL);
p0.h = hi(WDOG_CTL);
r0 = 0xAD6(z);
w[p0] = r0; /* watchdog off for now */
ssync;
/* Code update for BSS size == 0
* Zero out the bss region.
*/
p1.l = ___bss_start;
p1.h = ___bss_start;
p2.l = ___bss_stop;
p2.h = ___bss_stop;
r0 = 0;
p2 -= p1;
lsetup (.L_clear_bss, .L_clear_bss) lc0 = p2;
.L_clear_bss:
B[p1++] = r0;
/* In case there is a NULL pointer reference
* Zero out region before stext
*/
p1.l = 0x0;
p1.h = 0x0;
r0.l = __stext;
r0.h = __stext;
r0 = r0 >> 1;
p2 = r0;
r0 = 0;
lsetup (.L_clear_zero, .L_clear_zero) lc0 = p2;
.L_clear_zero:
W[p1++] = r0;
/* pass the uboot arguments to the global value command line */
R0 = R7;
call _cmdline_init;
p1.l = __rambase;
p1.h = __rambase;
r0.l = __sdata;
r0.h = __sdata;
[p1] = r0;
p1.l = __ramstart;
p1.h = __ramstart;
p3.l = ___bss_stop;
p3.h = ___bss_stop;
r1 = p3;
[p1] = r1;
/*
* load the current thread pointer and stack
*/
r1.l = _init_thread_union;
r1.h = _init_thread_union;
r2.l = 0x2000;
r2.h = 0x0000;
r1 = r1 + r2;
sp = r1;
usp = sp;
fp = sp;
call _start_kernel;
.L_exit:
jump.s .L_exit;
.section .l1.text
#if CONFIG_BFIN_KERNEL_CLOCK
ENTRY(_start_dma_code)
p0.h = hi(SIC_IWR);
p0.l = lo(SIC_IWR);
r0.l = 0x1;
r0.h = 0x0;
[p0] = r0;
SSYNC;
/*
* Set PLL_CTL
* - [14:09] = MSEL[5:0] : CLKIN / VCO multiplication factors
* - [8] = BYPASS : BYPASS the PLL, run CLKIN into CCLK/SCLK
* - [7] = output delay (add 200ps of delay to mem signals)
* - [6] = input delay (add 200ps of input delay to mem signals)
* - [5] = PDWN : 1=All Clocks off
* - [3] = STOPCK : 1=Core Clock off
* - [1] = PLL_OFF : 1=Disable Power to PLL
* - [0] = DF : 1=Pass CLKIN/2 to PLL / 0=Pass CLKIN to PLL
* all other bits set to zero
*/
p0.h = hi(PLL_LOCKCNT);
p0.l = lo(PLL_LOCKCNT);
r0 = 0x300(Z);
w[p0] = r0.l;
ssync;
P2.H = hi(EBIU_SDGCTL);
P2.L = lo(EBIU_SDGCTL);
R0 = [P2];
BITSET (R0, 24);
[P2] = R0;
SSYNC;
r0 = CONFIG_VCO_MULT & 63; /* Load the VCO multiplier */
r0 = r0 << 9; /* Shift it over, */
r1 = CLKIN_HALF; /* Do we need to divide CLKIN by 2?*/
r0 = r1 | r0;
r1 = PLL_BYPASS; /* Bypass the PLL? */
r1 = r1 << 8; /* Shift it over */
r0 = r1 | r0; /* add them all together */
p0.h = hi(PLL_CTL);
p0.l = lo(PLL_CTL); /* Load the address */
cli r2; /* Disable interrupts */
ssync;
w[p0] = r0.l; /* Set the value */
idle; /* Wait for the PLL to stablize */
sti r2; /* Enable interrupts */
.Lcheck_again:
p0.h = hi(PLL_STAT);
p0.l = lo(PLL_STAT);
R0 = W[P0](Z);
CC = BITTST(R0,5);
if ! CC jump .Lcheck_again;
/* Configure SCLK & CCLK Dividers */
r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
p0.h = hi(PLL_DIV);
p0.l = lo(PLL_DIV);
w[p0] = r0.l;
ssync;
p0.l = lo(EBIU_SDRRC);
p0.h = hi(EBIU_SDRRC);
r0 = mem_SDRRC;
w[p0] = r0.l;
ssync;
p0.l = (EBIU_SDBCTL & 0xFFFF);
p0.h = (EBIU_SDBCTL >> 16); /* SDRAM Memory Bank Control Register */
r0 = mem_SDBCTL;
w[p0] = r0.l;
ssync;
P2.H = hi(EBIU_SDGCTL);
P2.L = lo(EBIU_SDGCTL);
R0 = [P2];
BITCLR (R0, 24);
p0.h = hi(EBIU_SDSTAT);
p0.l = lo(EBIU_SDSTAT);
r2.l = w[p0];
cc = bittst(r2,3);
if !cc jump .Lskip;
NOP;
BITSET (R0, 23);
.Lskip:
[P2] = R0;
SSYNC;
R0.L = lo(mem_SDGCTL);
R0.H = hi(mem_SDGCTL);
R1 = [p2];
R1 = R1 | R0;
[P2] = R1;
SSYNC;
p0.h = hi(SIC_IWR);
p0.l = lo(SIC_IWR);
r0.l = lo(IWR_ENABLE_ALL)
r0.h = hi(IWR_ENABLE_ALL)
[p0] = r0;
SSYNC;
RTS;
#endif /* CONFIG_BFIN_KERNEL_CLOCK */
ENTRY(_bfin_reset)
/* No more interrupts to be handled*/
CLI R6;
SSYNC;
#if defined(CONFIG_BFIN_SHARED_FLASH_ENET)
p0.h = hi(FIO_INEN);
p0.l = lo(FIO_INEN);
r0.l = ~(1 << CONFIG_ENET_FLASH_PIN);
w[p0] = r0.l;
p0.h = hi(FIO_DIR);
p0.l = lo(FIO_DIR);
r0.l = (1 << CONFIG_ENET_FLASH_PIN);
w[p0] = r0.l;
p0.h = hi(FIO_FLAG_C);
p0.l = lo(FIO_FLAG_C);
r0.l = (1 << CONFIG_ENET_FLASH_PIN);
w[p0] = r0.l;
#endif
/* Clear the IMASK register */
p0.h = hi(IMASK);
p0.l = lo(IMASK);
r0 = 0x0;
[p0] = r0;
/* Clear the ILAT register */
p0.h = hi(ILAT);
p0.l = lo(ILAT);
r0 = [p0];
[p0] = r0;
SSYNC;
/* make sure SYSCR is set to use BMODE */
P0.h = hi(SYSCR);
P0.l = lo(SYSCR);
R0.l = 0x0;
W[P0] = R0.l;
SSYNC;
/* issue a system soft reset */
P1.h = hi(SWRST);
P1.l = lo(SWRST);
R1.l = 0x0007;
W[P1] = R1;
SSYNC;
/* clear system soft reset */
R0.l = 0x0000;
W[P0] = R0;
SSYNC;
/* issue core reset */
raise 1;
RTS;
ENDPROC(_bfin_reset)
#if CONFIG_DEBUG_KERNEL_START
debug_kernel_start_trap:
/* Set up a temp stack in L1 - SDRAM might not be working */
P0.L = lo(L1_DATA_A_START + 0x100);
P0.H = hi(L1_DATA_A_START + 0x100);
SP = P0;
/* Make sure the Clocks are the way I think they should be */
r0 = CONFIG_VCO_MULT & 63; /* Load the VCO multiplier */
r0 = r0 << 9; /* Shift it over, */
r1 = CLKIN_HALF; /* Do we need to divide CLKIN by 2?*/
r0 = r1 | r0;
r1 = PLL_BYPASS; /* Bypass the PLL? */
r1 = r1 << 8; /* Shift it over */
r0 = r1 | r0; /* add them all together */
p0.h = hi(PLL_CTL);
p0.l = lo(PLL_CTL); /* Load the address */
cli r2; /* Disable interrupts */
ssync;
w[p0] = r0.l; /* Set the value */
idle; /* Wait for the PLL to stablize */
sti r2; /* Enable interrupts */
.Lcheck_again1:
p0.h = hi(PLL_STAT);
p0.l = lo(PLL_STAT);
R0 = W[P0](Z);
CC = BITTST(R0,5);
if ! CC jump .Lcheck_again1;
/* Configure SCLK & CCLK Dividers */
r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
p0.h = hi(PLL_DIV);
p0.l = lo(PLL_DIV);
w[p0] = r0.l;
ssync;
/* Make sure UART is enabled - you can never be sure */
/*
* Setup for console. Argument comes from the menuconfig
*/
#ifdef CONFIG_BAUD_9600
#define CONSOLE_BAUD_RATE 9600
#elif CONFIG_BAUD_19200
#define CONSOLE_BAUD_RATE 19200
#elif CONFIG_BAUD_38400
#define CONSOLE_BAUD_RATE 38400
#elif CONFIG_BAUD_57600
#define CONSOLE_BAUD_RATE 57600
#elif CONFIG_BAUD_115200
#define CONSOLE_BAUD_RATE 115200
#endif
p0.h = hi(UART_GCTL);
p0.l = lo(UART_GCTL);
r0 = 0x00(Z);
w[p0] = r0.L; /* To Turn off UART clocks */
ssync;
p0.h = hi(UART_LCR);
p0.l = lo(UART_LCR);
r0 = 0x83(Z);
w[p0] = r0.L; /* To enable DLL writes */
ssync;
R1 = (((CONFIG_CLKIN_HZ * CONFIG_VCO_MULT) / CONFIG_SCLK_DIV) / (CONSOLE_BAUD_RATE * 16));
p0.h = hi(UART_DLL);
p0.l = lo(UART_DLL);
r0 = 0xFF(Z);
r0 = R1 & R0;
w[p0] = r0.L;
ssync;
p0.h = hi(UART_DLH);
p0.l = lo(UART_DLH);
r1 >>= 8 ;
w[p0] = r1.L;
ssync;
p0.h = hi(UART_GCTL);
p0.l = lo(UART_GCTL);
r0 = 0x0(Z);
w[p0] = r0.L; /* To enable UART clock */
ssync;
p0.h = hi(UART_LCR);
p0.l = lo(UART_LCR);
r0 = 0x03(Z);
w[p0] = r0.L; /* To Turn on UART */
ssync;
p0.h = hi(UART_GCTL);
p0.l = lo(UART_GCTL);
r0 = 0x01(Z);
w[p0] = r0.L; /* To Turn on UART Clocks */
ssync;
P0.h = hi(UART_THR);
P0.l = lo(UART_THR);
P1.h = hi(UART_LSR);
P1.l = lo(UART_LSR);
R0.L = 'K';
call .Lwait_char;
R0.L='e';
call .Lwait_char;
R0.L='r';
call .Lwait_char;
R0.L='n'
call .Lwait_char;
R0.L='e'
call .Lwait_char;
R0.L='l';
call .Lwait_char;
R0.L=' ';
call .Lwait_char;
R0.L='c';
call .Lwait_char;
R0.L='r';
call .Lwait_char;
R0.L='a';
call .Lwait_char;
R0.L='s';
call .Lwait_char;
R0.L='h';
call .Lwait_char;
R0.L='\r';
call .Lwait_char;
R0.L='\n';
call .Lwait_char;
R0.L='S';
call .Lwait_char;
R0.L='E';
call .Lwait_char;
R0.L='Q'
call .Lwait_char;
R0.L='S'
call .Lwait_char;
R0.L='T';
call .Lwait_char;
R0.L='A';
call .Lwait_char;
R0.L='T';
call .Lwait_char;
R0.L='=';
call .Lwait_char;
R2 = SEQSTAT;
call .Ldump_reg;
R0.L=' ';
call .Lwait_char;
R0.L='R';
call .Lwait_char;
R0.L='E'
call .Lwait_char;
R0.L='T'
call .Lwait_char;
R0.L='X';
call .Lwait_char;
R0.L='=';
call .Lwait_char;
R2 = RETX;
call .Ldump_reg;
R0.L='\r';
call .Lwait_char;
R0.L='\n';
call .Lwait_char;
.Ldebug_kernel_start_trap_done:
JUMP .Ldebug_kernel_start_trap_done;
.Ldump_reg:
R3 = 32;
R4 = 0x0F;
R5 = ':'; /* one past 9 */
.Ldump_reg2:
R0 = R2;
R3 += -4;
R0 >>>= R3;
R0 = R0 & R4;
R0 += 0x30;
CC = R0 <= R5;
if CC JUMP .Ldump_reg1;
R0 += 7;
.Ldump_reg1:
R1.l = W[P1];
CC = BITTST(R1, 5);
if !CC JUMP .Ldump_reg1;
W[P0] = r0;
CC = R3 == 0;
if !CC JUMP .Ldump_reg2
RTS;
.Lwait_char:
R1.l = W[P1];
CC = BITTST(R1, 5);
if !CC JUMP .Lwait_char;
W[P0] = r0;
RTS;
#endif /* CONFIG_DEBUG_KERNEL_START */
.data
/*
* Set up the usable of RAM stuff. Size of RAM is determined then
* an initial stack set up at the end.
*/
.align 4
__rambase:
.long 0
__ramstart:
.long 0
__ramend:
.long 0