Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 516 insertions, 0 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
new file mode 100644
index 0000000..171b3e8
--- /dev/null
+++ b/arch/arm/kernel/head.S
@@ -0,0 +1,516 @@
+/*
+ *  linux/arch/arm/kernel/head.S
+ *
+ *  Copyright (C) 1994-2002 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  Kernel startup code for all 32-bit CPUs
+ */
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/assembler.h>
+#include <asm/domain.h>
+#include <asm/mach-types.h>
+#include <asm/procinfo.h>
+#include <asm/ptrace.h>
+#include <asm/constants.h>
+#include <asm/system.h>
+
+#define PROCINFO_MMUFLAGS	8
+#define PROCINFO_INITFUNC	12
+
+#define MACHINFO_TYPE		0
+#define MACHINFO_PHYSRAM	4
+#define MACHINFO_PHYSIO		8
+#define MACHINFO_PGOFFIO	12
+#define MACHINFO_NAME		16
+
+#ifndef CONFIG_XIP_KERNEL
+/*
+ * We place the page tables 16K below TEXTADDR.  Therefore, we must make sure
+ * that TEXTADDR is correctly set.  Currently, we expect the least significant
+ * 16 bits to be 0x8000, but we could probably relax this restriction to
+ * TEXTADDR >= PAGE_OFFSET + 0x4000
+ *
+ * Note that swapper_pg_dir is the virtual address of the page tables, and
+ * pgtbl gives us a position-independent reference to these tables.  We can
+ * do this because stext == TEXTADDR
+ */
+#if (TEXTADDR & 0xffff) != 0x8000
+#error TEXTADDR must start at 0xXXXX8000
+#endif
+
+	.globl	swapper_pg_dir
+	.equ	swapper_pg_dir, TEXTADDR - 0x4000
+
+	.macro	pgtbl, rd, phys
+	adr	\rd, stext
+	sub	\rd, \rd, #0x4000
+	.endm
+#else
+/*
+ * XIP Kernel:
+ *
+ * We place the page tables 16K below DATAADDR.  Therefore, we must make sure
+ * that DATAADDR is correctly set.  Currently, we expect the least significant
+ * 16 bits to be 0x8000, but we could probably relax this restriction to
+ * DATAADDR >= PAGE_OFFSET + 0x4000
+ *
+ * Note that pgtbl is meant to return the physical address of swapper_pg_dir.
+ * We can't make it relative to the kernel position in this case since
+ * the kernel can physically be anywhere.
+ */
+#if (DATAADDR & 0xffff) != 0x8000
+#error DATAADDR must start at 0xXXXX8000
+#endif
+
+	.globl	swapper_pg_dir
+	.equ	swapper_pg_dir, DATAADDR - 0x4000
+
+	.macro	pgtbl, rd, phys
+	ldr	\rd, =((DATAADDR - 0x4000) - VIRT_OFFSET)
+	add	\rd, \rd, \phys
+	.endm
+#endif
+
+/*
+ * Kernel startup entry point.
+ * ---------------------------
+ *
+ * This is normally called from the decompressor code.  The requirements
+ * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
+ * r1 = machine nr.
+ *
+ * This code is mostly position independent, so if you link the kernel at
+ * 0xc0008000, you call this at __pa(0xc0008000).
+ *
+ * See linux/arch/arm/tools/mach-types for the complete list of machine
+ * numbers for r1.
+ *
+ * We're trying to keep crap to a minimum; DO NOT add any machine specific
+ * crap here - that's what the boot loader (or in extreme, well justified
+ * circumstances, zImage) is for.
+ */
+	__INIT
+	.type	stext, %function
+ENTRY(stext)
+	msr	cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
+						@ and irqs disabled
+	bl	__lookup_processor_type		@ r5=procinfo r9=cpuid
+	movs	r10, r5				@ invalid processor (r5=0)?
+	beq	__error_p				@ yes, error 'p'
+	bl	__lookup_machine_type		@ r5=machinfo
+	movs	r8, r5				@ invalid machine (r5=0)?
+	beq	__error_a			@ yes, error 'a'
+	bl	__create_page_tables
+
+	/*
+	 * The following calls CPU specific code in a position independent
+	 * manner.  See arch/arm/mm/proc-*.S for details.  r10 = base of
+	 * xxx_proc_info structure selected by __lookup_machine_type
+	 * above.  On return, the CPU will be ready for the MMU to be
+	 * turned on, and r0 will hold the CPU control register value.
+	 */
+	ldr	r13, __switch_data		@ address to jump to after
+						@ mmu has been enabled
+	adr	lr, __enable_mmu		@ return (PIC) address
+	add	pc, r10, #PROCINFO_INITFUNC
+
+	.type	__switch_data, %object
+__switch_data:
+	.long	__mmap_switched
+	.long	__data_loc			@ r4
+	.long	__data_start			@ r5
+	.long	__bss_start			@ r6
+	.long	_end				@ r7
+	.long	processor_id			@ r4
+	.long	__machine_arch_type		@ r5
+	.long	cr_alignment			@ r6
+	.long	init_thread_union+8192		@ sp
+
+/*
+ * The following fragment of code is executed with the MMU on, and uses
+ * absolute addresses; this is not position independent.
+ *
+ *  r0  = cp#15 control register
+ *  r1  = machine ID
+ *  r9  = processor ID
+ */
+	.type	__mmap_switched, %function
+__mmap_switched:
+	adr	r3, __switch_data + 4
+
+	ldmia	r3!, {r4, r5, r6, r7}
+	cmp	r4, r5				@ Copy data segment if needed
+1:	cmpne	r5, r6
+	ldrne	fp, [r4], #4
+	strne	fp, [r5], #4
+	bne	1b
+
+	mov	fp, #0				@ Clear BSS (and zero fp)
+1:	cmp	r6, r7
+	strcc	fp, [r6],#4
+	bcc	1b
+
+	ldmia	r3, {r4, r5, r6, sp}
+	str	r9, [r4]			@ Save processor ID
+	str	r1, [r5]			@ Save machine type
+	bic	r4, r0, #CR_A			@ Clear 'A' bit
+	stmia	r6, {r0, r4}			@ Save control register values
+	b	start_kernel
+
+
+
+/*
+ * Setup common bits before finally enabling the MMU.  Essentially
+ * this is just loading the page table pointer and domain access
+ * registers.
+ */
+	.type	__enable_mmu, %function
+__enable_mmu:
+#ifdef CONFIG_ALIGNMENT_TRAP
+	orr	r0, r0, #CR_A
+#else
+	bic	r0, r0, #CR_A
+#endif
+#ifdef CONFIG_CPU_DCACHE_DISABLE
+	bic	r0, r0, #CR_C
+#endif
+#ifdef CONFIG_CPU_BPREDICT_DISABLE
+	bic	r0, r0, #CR_Z
+#endif
+#ifdef CONFIG_CPU_ICACHE_DISABLE
+	bic	r0, r0, #CR_I
+#endif
+	mov	r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
+		      domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
+		      domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
+		      domain_val(DOMAIN_IO, DOMAIN_CLIENT))
+	mcr	p15, 0, r5, c3, c0, 0		@ load domain access register
+	mcr	p15, 0, r4, c2, c0, 0		@ load page table pointer
+	b	__turn_mmu_on
+
+/*
+ * Enable the MMU.  This completely changes the structure of the visible
+ * memory space.  You will not be able to trace execution through this.
+ * If you have an enquiry about this, *please* check the linux-arm-kernel
+ * mailing list archives BEFORE sending another post to the list.
+ *
+ *  r0  = cp#15 control register
+ *  r13 = *virtual* address to jump to upon completion
+ *
+ * other registers depend on the function called upon completion
+ */
+	.align	5
+	.type	__turn_mmu_on, %function
+__turn_mmu_on:
+	mov	r0, r0
+	mcr	p15, 0, r0, c1, c0, 0		@ write control reg
+	mrc	p15, 0, r3, c0, c0, 0		@ read id reg
+	mov	r3, r3
+	mov	r3, r3
+	mov	pc, r13
+
+
+
+/*
+ * Setup the initial page tables.  We only setup the barest
+ * amount which are required to get the kernel running, which
+ * generally means mapping in the kernel code.
+ *
+ * r8  = machinfo
+ * r9  = cpuid
+ * r10 = procinfo
+ *
+ * Returns:
+ *  r0, r3, r5, r6, r7 corrupted
+ *  r4 = physical page table address
+ */
+	.type	__create_page_tables, %function
+__create_page_tables:
+	ldr	r5, [r8, #MACHINFO_PHYSRAM]	@ physram
+	pgtbl	r4, r5				@ page table address
+
+	/*
+	 * Clear the 16K level 1 swapper page table
+	 */
+	mov	r0, r4
+	mov	r3, #0
+	add	r6, r0, #0x4000
+1:	str	r3, [r0], #4
+	str	r3, [r0], #4
+	str	r3, [r0], #4
+	str	r3, [r0], #4
+	teq	r0, r6
+	bne	1b
+
+	ldr	r7, [r10, #PROCINFO_MMUFLAGS]	@ mmuflags
+
+	/*
+	 * Create identity mapping for first MB of kernel to
+	 * cater for the MMU enable.  This identity mapping
+	 * will be removed by paging_init().  We use our current program
+	 * counter to determine corresponding section base address.
+	 */
+	mov	r6, pc, lsr #20			@ start of kernel section
+	orr	r3, r7, r6, lsl #20		@ flags + kernel base
+	str	r3, [r4, r6, lsl #2]		@ identity mapping
+
+	/*
+	 * Now setup the pagetables for our kernel direct
+	 * mapped region.  We round TEXTADDR down to the
+	 * nearest megabyte boundary.  It is assumed that
+	 * the kernel fits within 4 contigous 1MB sections.
+	 */
+	add	r0, r4,  #(TEXTADDR & 0xff000000) >> 18	@ start of kernel
+	str	r3, [r0, #(TEXTADDR & 0x00f00000) >> 18]!
+	add	r3, r3, #1 << 20
+	str	r3, [r0, #4]!			@ KERNEL + 1MB
+	add	r3, r3, #1 << 20
+	str	r3, [r0, #4]!			@ KERNEL + 2MB
+	add	r3, r3, #1 << 20
+	str	r3, [r0, #4]			@ KERNEL + 3MB
+
+	/*
+	 * Then map first 1MB of ram in case it contains our boot params.
+	 */
+	add	r0, r4, #VIRT_OFFSET >> 18
+	orr	r6, r5, r7
+	str	r6, [r0]
+
+#ifdef CONFIG_XIP_KERNEL
+	/*
+	 * Map some ram to cover our .data and .bss areas.
+	 * Mapping 3MB should be plenty.
+	 */
+	sub	r3, r4, r5
+	mov	r3, r3, lsr #20
+	add	r0, r0, r3, lsl #2
+	add	r6, r6, r3, lsl #20
+	str	r6, [r0], #4
+	add	r6, r6, #(1 << 20)
+	str	r6, [r0], #4
+	add	r6, r6, #(1 << 20)
+	str	r6, [r0]
+#endif
+
+	bic	r7, r7, #0x0c			@ turn off cacheable
+						@ and bufferable bits
+#ifdef CONFIG_DEBUG_LL
+	/*
+	 * Map in IO space for serial debugging.
+	 * This allows debug messages to be output
+	 * via a serial console before paging_init.
+	 */
+	ldr	r3, [r8, #MACHINFO_PGOFFIO]
+	add	r0, r4, r3
+	rsb	r3, r3, #0x4000			@ PTRS_PER_PGD*sizeof(long)
+	cmp	r3, #0x0800			@ limit to 512MB
+	movhi	r3, #0x0800
+	add	r6, r0, r3
+	ldr	r3, [r8, #MACHINFO_PHYSIO]
+	orr	r3, r3, r7
+1:	str	r3, [r0], #4
+	add	r3, r3, #1 << 20
+	teq	r0, r6
+	bne	1b
+#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
+	/*
+	 * If we're using the NetWinder, we need to map in
+	 * the 16550-type serial port for the debug messages
+	 */
+	teq	r1, #MACH_TYPE_NETWINDER
+	teqne	r1, #MACH_TYPE_CATS
+	bne	1f
+	add	r0, r4, #0x3fc0			@ ff000000
+	mov	r3, #0x7c000000
+	orr	r3, r3, r7
+	str	r3, [r0], #4
+	add	r3, r3, #1 << 20
+	str	r3, [r0], #4
+1:
+#endif
+#endif
+#ifdef CONFIG_ARCH_RPC
+	/*
+	 * Map in screen at 0x02000000 & SCREEN2_BASE
+	 * Similar reasons here - for debug.  This is
+	 * only for Acorn RiscPC architectures.
+	 */
+	add	r0, r4, #0x80			@ 02000000
+	mov	r3, #0x02000000
+	orr	r3, r3, r7
+	str	r3, [r0]
+	add	r0, r4, #0x3600			@ d8000000
+	str	r3, [r0]
+#endif
+	mov	pc, lr
+	.ltorg
+
+
+
+/*
+ * Exception handling.  Something went wrong and we can't proceed.  We
+ * ought to tell the user, but since we don't have any guarantee that
+ * we're even running on the right architecture, we do virtually nothing.
+ *
+ * If CONFIG_DEBUG_LL is set we try to print out something about the error
+ * and hope for the best (useful if bootloader fails to pass a proper
+ * machine ID for example).
+ */
+
+	.type	__error_p, %function
+__error_p:
+#ifdef CONFIG_DEBUG_LL
+	adr	r0, str_p1
+	bl	printascii
+	b	__error
+str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant.\n"
+	.align
+#endif
+
+	.type	__error_a, %function
+__error_a:
+#ifdef CONFIG_DEBUG_LL
+	mov	r4, r1				@ preserve machine ID
+	adr	r0, str_a1
+	bl	printascii
+	mov	r0, r4
+	bl	printhex8
+	adr	r0, str_a2
+	bl	printascii
+	adr	r3, 3f
+	ldmia	r3, {r4, r5, r6}		@ get machine desc list
+	sub	r4, r3, r4			@ get offset between virt&phys
+	add	r5, r5, r4			@ convert virt addresses to
+	add	r6, r6, r4			@ physical address space
+1:	ldr	r0, [r5, #MACHINFO_TYPE]	@ get machine type
+	bl	printhex8
+	mov	r0, #'\t'
+	bl	printch
+	ldr     r0, [r5, #MACHINFO_NAME]	@ get machine name
+	add	r0, r0, r4
+	bl	printascii
+	mov	r0, #'\n'
+	bl	printch
+	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc
+	cmp	r5, r6
+	blo	1b
+	adr	r0, str_a3
+	bl	printascii
+	b	__error
+str_a1:	.asciz	"\nError: unrecognized/unsupported machine ID (r1 = 0x"
+str_a2:	.asciz	").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"
+str_a3:	.asciz	"\nPlease check your kernel config and/or bootloader.\n"
+	.align
+#endif
+
+	.type	__error, %function
+__error:
+#ifdef CONFIG_ARCH_RPC
+/*
+ * Turn the screen red on a error - RiscPC only.
+ */
+	mov	r0, #0x02000000
+	mov	r3, #0x11
+	orr	r3, r3, r3, lsl #8
+	orr	r3, r3, r3, lsl #16
+	str	r3, [r0], #4
+	str	r3, [r0], #4
+	str	r3, [r0], #4
+	str	r3, [r0], #4
+#endif
+1:	mov	r0, r0
+	b	1b
+
+
+/*
+ * Read processor ID register (CP#15, CR0), and look up in the linker-built
+ * supported processor list.  Note that we can't use the absolute addresses
+ * for the __proc_info lists since we aren't running with the MMU on
+ * (and therefore, we are not in the correct address space).  We have to
+ * calculate the offset.
+ *
+ * Returns:
+ *	r3, r4, r6 corrupted
+ *	r5 = proc_info pointer in physical address space
+ *	r9 = cpuid
+ */
+	.type	__lookup_processor_type, %function
+__lookup_processor_type:
+	adr	r3, 3f
+	ldmda	r3, {r5, r6, r9}
+	sub	r3, r3, r9			@ get offset between virt&phys
+	add	r5, r5, r3			@ convert virt addresses to
+	add	r6, r6, r3			@ physical address space
+	mrc	p15, 0, r9, c0, c0		@ get processor id
+1:	ldmia	r5, {r3, r4}			@ value, mask
+	and	r4, r4, r9			@ mask wanted bits
+	teq	r3, r4
+	beq	2f
+	add	r5, r5, #PROC_INFO_SZ		@ sizeof(proc_info_list)
+	cmp	r5, r6
+	blo	1b
+	mov	r5, #0				@ unknown processor
+2:	mov	pc, lr
+
+/*
+ * This provides a C-API version of the above function.
+ */
+ENTRY(lookup_processor_type)
+	stmfd	sp!, {r4 - r6, r9, lr}
+	bl	__lookup_processor_type
+	mov	r0, r5
+	ldmfd	sp!, {r4 - r6, r9, pc}
+
+/*
+ * Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for
+ * more information about the __proc_info and __arch_info structures.
+ */
+	.long	__proc_info_begin
+	.long	__proc_info_end
+3:	.long	.
+	.long	__arch_info_begin
+	.long	__arch_info_end
+
+/*
+ * Lookup machine architecture in the linker-build list of architectures.
+ * Note that we can't use the absolute addresses for the __arch_info
+ * lists since we aren't running with the MMU on (and therefore, we are
+ * not in the correct address space).  We have to calculate the offset.
+ *
+ *  r1 = machine architecture number
+ * Returns:
+ *  r3, r4, r6 corrupted
+ *  r5 = mach_info pointer in physical address space
+ */
+	.type	__lookup_machine_type, %function
+__lookup_machine_type:
+	adr	r3, 3b
+	ldmia	r3, {r4, r5, r6}
+	sub	r3, r3, r4			@ get offset between virt&phys
+	add	r5, r5, r3			@ convert virt addresses to
+	add	r6, r6, r3			@ physical address space
+1:	ldr	r3, [r5, #MACHINFO_TYPE]	@ get machine type
+	teq	r3, r1				@ matches loader number?
+	beq	2f				@ found
+	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc
+	cmp	r5, r6
+	blo	1b
+	mov	r5, #0				@ unknown machine
+2:	mov	pc, lr
+
+/*
+ * This provides a C-API version of the above function.
+ */
+ENTRY(lookup_machine_type)
+	stmfd	sp!, {r4 - r6, lr}
+	mov	r1, r0
+	bl	__lookup_machine_type
+	mov	r0, r5
+	ldmfd	sp!, {r4 - r6, pc}