microblaze/kernel/head.S

2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2007-2009 PetaLogix
7  *    Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
12  *      Low-level exception handers, MMU support, and rewrite.
15  *    Copyright (c) 1998-1999 TiVo, Inc.
75  * r8 == 0 - msr instructions are implemented
76  * r8 != 0 - msr instructions are not implemented
79 	msrclr	r8, 0 /* clear nothing - just read msr for test */
85    is broken or non-existent */
89 	/* Save 1 as word and load byte - 0 - BIG, 1 - LITTLE */
98 	bnei	r11, no_fdt_arg			/* No - get out of here */
102 	ori	r3, r0, (0x10000 - 4)
105 	sw	r12, r4, r11 /* addr[r4 + r11] = r12 */
108 	addik	r3, r3, -4 /* descrement loop */
122 	ori	r3, r0, COMMAND_LINE_SIZE - 1 /* number of loops */
124 	/* r2=r5+r11 - r5 contain pointer to command line */
130 	addik	r3, r3, -1		/* decrement loop */
140 	ori	r3, r0, (LMB_SIZE - 4)
143 	sw	r7, r4, r11		/* addr[r4 + r11] = r7 */
146 	addik	r3, r3, -4		/* descrement loop */
156 	addik	r3, r0, MICROBLAZE_TLB_SIZE -1	/* Invalidate all TLB entries */
162 	addik	r3, r3, -1
188 	addik	r11, r12, -0x1000000
190 	addik	r11, r12, -0x0800000
192 	addik	r11, r12, -0x0400000
195 	addik	r11, r12, -0x0200000
198 	addik	r11, r12, -0x0100000
202 GT4: /* r11 contains the rest - will be either 1 or 4 */
209 	addik	r2, r11, -0x0400000
212 	addik	r11, r11, -0x0100000
219 GT17: /* TLB1 is 4MB - kernel size <20MB */
223 GT20: /* TLB1 is 16MB - kernel size >20MB */
237 	 * TLB0 is always used - check if is not zero (r9 stores TLB0 value)
307 	 * the exception vectors, using a 4k real==virtual mapping.
309 	/* Use temporary TLB_ID for LMB - clear this temporary mapping later */
339 	addik	r1, r0, init_thread_union + THREAD_SIZE - 4
360 	 * and change to using our exception vectors.