/////////////////////////////////////////////////////////////////////////////////// Copyright(c) 2001-2002 Hybus Co,.ltd. All rights reserved.//// Module name://      start_xscale.S//// Description:////// Author://      bedguy//// Created://      2002.10/////////////////////////////////////////////////////////////////////////////////#include <start_xscale.h>#include <config.h>.text.extern _ld_text_start.extern _ld_text_and_data_size//////////////////////////////////////////////////////////////////////////////////////////		Vector Table				//////////////////////////////////////////////////////////////////////////////////////////////.globl _start_start:        b       resetreset:	// Mask All interrupt         ldr     r12, =INTERRUPT_CONTROL_BASE        ldr     r0, =0x00000000        str     r0, [r12, #ICMR]        str     r0, [r12, #ICLR]	// Initialize GPIO        bl      gpio_init	// Initialize SDRAM        bl      init_sdram	// Copy Bootloader from Flash to SDRAM	bl	copy_to_ram		// Loading kernel image        ldr	r4, =KERNEL_SRAM_BASE        ldr	r5, =KERNEL_DRAM_BASE        ldr	r6, =KERNEL_MAX_SIZE        add	r6, r6, r4repeat:        ldmia   r4!, {r0-r3, r7-r10}        stmia   r5!, {r0-r3, r7-r10}        cmp             r4, r6        blt             repeat	ldr	sp, =_ld_stack_address	// Jump to c_main	ldr	r0, =c_main	mov	pc, r0die:	b	die//////////////////////////////////////////////////////////////////////////////////////////		Initialize GPIO				//////////////////////////////////////////////////////////////////////////////////////////////gpio_init:	ldr     r12, =GPIO_BASE    ldr     r0, =GAFR0L_VALUE //0x80000000    str     r0, [r12, #GAFR0_L]//0x54    ldr     r0, =GAFR0U_VALUE		//0xA5000010    str     r0, [r12, #GAFR0_U]	//0x58    ldr     r0, =GAFR1L_VALUE		//0x60008018    str     r0, [r12, #GAFR1_L]    ldr     r0, =GAFR1U_VALUE		// 0xAAA5AAAA    str     r0, [r12, #GAFR1_U]    ldr     r0, =GAFR2L_VALUE		//0xAAA0000A    str     r0, [r12, #GAFR2_L]    ldr     r0, =GAFR2U_VALUE		//0x00000002    str     r0, [r12, #GAFR2_U]    ldr     r0, =GPSR0_VALUE    str     r0, [r12, #GPSR0]    ldr     r0, =GPSR1_VALUE    str     r0, [r12, #GPSR1]    ldr     r0, =GPSR2_VALUE    str     r0, [r12, #GPSR2]    ldr     r0, =GPCR0_VALUE    str     r0, [r12, #GPCR0]    ldr     r0, =GPCR1_VALUE    str     r0, [r12, #GPCR1]    ldr     r0, =GPCR2_VALUE    str     r0, [r12, #GPCR2]    ldr     r0, =GPDR0_VALUE    str     r0, [r12, #GPDR0]    ldr     r0, =GPDR1_VALUE    str     r0, [r12, #GPDR1]    ldr     r0, =GPDR2_VALUE    str     r0, [r12, #GPDR2]        // Clear the peripheral control register bits	ldr     r1, =PSSR	ldr     r2, =(PSSR_RDH | PSSR_PH)	str     r2, [r1]        	mov     pc, lr//////////////////////////////////////////////////////////////////////////////////////////	 	Initialize SDRAM			//////////////////////////////////////////////////////////////////////////////////////////////init_sdram:	mov	r10, lr        ldr     r12, =CLOCK_MANAGER_BASE        ldr     r0, =CKEN_VALUE        str     r0, [r12, #CKEN]        ldr     r0, =OSCC_VALUE        str     r0, [r12, #OSCC]#if 1//TODO: Issuing a FCS on a B1 seems to make it crash//shortly after. Figure out why...        ldr     r0, =CCCR_VALUE        str     r0, [r12, #CCCR]        mov     r1, #3        mcr     p14, 0, r1, c6, c0, 0	ldr	r1, =OSCR	ldr	r0, =0	str	r0, [r1]        ldr     r0, =0x300wait_for_clock:        ldr	r2, [r1]        cmp     r0, r2        bne     wait_for_clock#endif        //Step 1 in Intel's code        ldr     r12, =MEM_CTL_BASE        ldr     r0, =MSC0_VALUE        str     r0, [r12, #MSC0]        //Intel's code reads it back to make sure it works...    //    ldr     r0, [r12, #MSC0]        ldr     r0, =MSC1_VALUE        str     r0, [r12, #MSC1]        ldr     r0, [r12, #MSC1]        ldr     r0, =MSC2_VALUE        str     r0, [r12, #MSC2]        ldr     r0, [r12, #MSC2]        ldr     r0, =MECR_VALUE        str     r0, [r12, #MECR]        ldr     r0, =MCMEM0_VALUE        str     r0, [r12, #MCMEM0]        ldr     r0, =MCMEM1_VALUE        str     r0, [r12, #MCMEM1]        ldr     r0, =MCATT0_VALUE        str     r0, [r12, #MCATT0]        ldr     r0, =MCATT1_VALUE        str     r0, [r12, #MCATT1]        ldr     r0, =MCIO0_VALUE        str     r0, [r12, #MCIO0]        ldr     r0, =MCIO1_VALUE        str     r0, [r12, #MCIO1]        //according to Intel's comments, we're extracting the DRI	// Loading the MDREFR in a way that will make it configure	// correctly is a multi-step process.  Please read Section	// 6.12 of the PXA Developers Manual For more Details	// 1.	// The first step requires that we set K0RUN and E0PIN while	// configuring DRI and clearing KXFREE.  All other values	// MUST be left alone        ldr     r0, =MDREFR_VALUE        ldr     r3, [r12, #MDREFR]        ldr     r1, =0xFFF        and     r0, r0, r1	// Make the DRI we read from MDREFR what MDREFR_VALUE says it is.	// We also Free KXFREE the free running bits.        bic     r3, r3, r1	bic	r3, r3, #0x03800000        orr     r3, r3, r0        //Write it back        str     r3, [r12, #MDREFR]	// 2.	// We don't have Synchronous Static Memory and don't want to	// mess with SXCNFG or the like so we are leaving out this	// step.	// 3.	// We don't bother to do this step as it does not seem to have	// been done previously (actually maybe Self-Refresh Disable should	// be here.)        // 4.	// Here we will setup the SDCLK's but WILL NOT enable them.  We	// need to reload MDREFR for this.        ldr     r0, =MDREFR_VALUE	ldr	r1, =0xF6000	// Mask of SDCLK's settings minus EXPIN	and	r0, r0, r1        bic     r3, r3, r1	orr	r3, r3, r0        str     r3, [r12, #MDREFR]	ldr	r3, [r12, #MDREFR]	// 4.        // Although I think that this should be at #3 It is here cause this	// is where it was originally.  This will turn off Self-Refresh.        bic     r3, r3, #0x00400000        str     r3, [r12, #MDREFR]	// 5.	// Finally, we Enable the Various SDCLK's and let it run.	// Also, enable the free-running clocks (not mentioned in the manual).	ldr	r0, =MDREFR_VALUE	ldr	r1, =0x03809000	and	r0, r0, r1	orr	r3, r3, r0        str     r3, [r12, #MDREFR]        nop        nop        //Step 4 in Intel's code        ldr     r0, =MDCNFG_VALUE        //disable all sdram banks        bic     r0, r0, #0x00000003        bic     r0, r0, #0x00030000        //program banks 0/1 for 32 bit bus width        bic     r0, r0, #0x00000004	//test with 16 bit bus width//	orr	r0, r0, #0x00000004        //write MDCNFG, without enabling SDRAM banks        str     r0, [r12, #MDCNFG]        //Step 5 in Intel's code        ldr     r0, =OSCR	mov	r1, #0	str	r1, [r0]        //pause for approx 200 usecs        ldr     r4, =0x300sdram_dly:        ldr     r1, [r0]        cmp     r4, r1        bgt     sdram_dly        //Step 6 in Intel's code        //turn everything off        mov     r0, #0x78        mcr     p15, 0, r0, c1, c0, 0        //Step 7 in Intel's code        //Access memory that has not been enabled for CBR refresh cycles (8)	ldr	r0, =SDRAM_BASE        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        str     r0, [r0]        //Step 8 is blank in Intel's code, though they mention dcache should        //be enabled here if it is desired (we don't care)        //Step 9        ldr     r0, [r12, #MDCNFG]        //enable bank 0 (what about bank 1?)        orr     r0, r0, #0x00000001        str     r0, [r12, #MDCNFG]        //Step 10        //write MDMRS again        ldr     r0, =MDMRS_VALUE        str     r0, [r12, #MDMRS]        //Step 11        //are we A1_Cotulla?        ldr     r0, [r12, #MDREFR]	ldr	r11, =0xFFEFFFFF	and	r0, r0, r11        str     r0, [r12, #MDREFR]        mov     pc, r10//////////////////////////////////////////////////////////////////////////////////////////	 Copy Bootloader from Flash to SDRAM		//////////////////////////////////////////////////////////////////////////////////////////////copy_to_ram:	mov	r8, lr	ldr	r0, =0	ldr	r1, =_ld_text_start	ldr	r2, =_ld_text_and_data_sizecopy_loop:	ldr	r3, [r0]	str	r3, [r1]	add	r0, r0, #4	add	r1, r1, #4	subs	r2, r2, #4	bne	copy_loop	mov	pc, r8