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, 128 insertions, 0 deletions

diff --git a/arch/v850/kernel/head.S b/arch/v850/kernel/head.S
new file mode 100644
index 00000000000..c490b937ef1
--- /dev/null
+++ b/arch/v850/kernel/head.S
@@ -0,0 +1,128 @@
+/*
+ * arch/v850/kernel/head.S -- Lowest-level startup code
+ *
+ *  Copyright (C) 2001,02,03  NEC Electronics Corporation
+ *  Copyright (C) 2001,02,03  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <asm/clinkage.h>
+#include <asm/current.h>
+#include <asm/entry.h>
+#include <asm/thread_info.h>
+#include <asm/irq.h>
+
+
+/* Make a slightly more convenient alias for C_SYMBOL_NAME.  */
+#define CSYM	C_SYMBOL_NAME
+
+
+	.text
+
+	// Define `mach_early_init' as a weak symbol
+	.global	CSYM(mach_early_init)
+	.weak	CSYM(mach_early_init)
+
+C_ENTRY(start):
+	// Make sure interrupts are turned off, just in case
+	di
+
+#ifdef CONFIG_RESET_GUARD
+	// See if we got here via an unexpected reset
+	ld.w	RESET_GUARD, r19	// Check current value of reset guard
+	mov	RESET_GUARD_ACTIVE, r20
+	cmp	r19, r20
+	bne	1f			// Guard was not active
+
+	// If we get here, the reset guard was active.  Load up some
+	// interesting values as arguments, and jump to the handler.
+	st.w	r0, RESET_GUARD		// Allow further resets to succeed
+	mov	lp, r6			// Arg 0: return address
+	ld.b	KM, r7			// Arg 1: kernel mode
+	mov	sp, r9			// Arg 3: stack pointer
+	ld.w	KSP, r19		// maybe switch to kernel stack
+	cmp	r7, r0			// see if already in kernel mode
+	cmov	z, r19, sp, sp		//  and switch to kernel stack if not
+	GET_CURRENT_TASK(r8)		// Arg 2: task pointer
+	jr	CSYM(unexpected_reset)
+
+1:	st.w	r20, RESET_GUARD	// Turn on reset guard
+#endif /* CONFIG_RESET_GUARD */
+
+	// Setup a temporary stack for doing pre-initialization function calls.
+	// 
+	// We can't use the initial kernel stack, because (1) it may be
+	// located in memory we're not allowed to touch, and (2) since
+	// it's in the data segment, calling memcpy to initialize that
+	// area from ROM will overwrite memcpy's return address.
+	mov	hilo(CSYM(_init_stack_end) - 4), sp
+
+	// See if there's a platform-specific early-initialization routine
+	// defined; it's a weak symbol, so it will have an address of zero if
+	// there's not.
+	mov	hilo(CSYM(mach_early_init)), r6
+	cmp	r6, r0
+	bz	3f
+
+	// There is one, so call it.  If this function is written in C, it
+	// should be very careful -- the stack pointer is valid, but very
+	// little else is (e.g., bss is not zeroed yet, and initialized data
+	// hasn't been).
+	jarl	2f, lp			// first figure out return address
+2:	add	3f - ., lp
+	jmp	[r6]			// do call
+3:
+
+#ifdef CONFIG_ROM_KERNEL
+	// Copy the data area from ROM to RAM
+	mov	hilo(CSYM(_rom_copy_dst_start)), r6
+	mov	hilo(CSYM(_rom_copy_src_start)), r7
+	mov	hilo(CSYM(_rom_copy_dst_end)), r8
+	sub	r6, r8
+	jarl	CSYM(memcpy), lp
+#endif
+
+	// Load the initial thread's stack, and current task pointer (in r16)
+	mov	hilo(CSYM(init_thread_union)), r19
+	movea	THREAD_SIZE, r19, sp
+	ld.w	TI_TASK[r19], CURRENT_TASK
+
+#ifdef CONFIG_TIME_BOOTUP
+	/* This stuff must come after mach_early_init, because interrupts may
+	   not work until after its been called.  */
+	jarl	CSYM(highres_timer_reset), lp
+	jarl	CSYM(highres_timer_start), lp
+#endif
+
+	// Kernel stack pointer save location
+	st.w	sp, KSP
+
+	// Assert that we're in `kernel mode'
+	mov	1, r19
+	st.w	r19, KM
+
+#ifdef CONFIG_ZERO_BSS
+	// Zero bss area, since we can't rely upon any loader to do so
+	mov	hilo(CSYM(_sbss)), r6
+	mov	r0, r7
+	mov	hilo(CSYM(_ebss)), r8
+	sub	r6, r8
+	jarl	CSYM(memset), lp
+#endif
+
+	// What happens if the main kernel function returns (it shouldn't)
+	mov	hilo(CSYM(machine_halt)), lp
+
+	// Start the linux kernel.  We use an indirect jump to get extra
+	// range, because on some platforms this initial startup code
+	// (and the associated platform-specific code in mach_early_init)
+	// are located far away from the main kernel, e.g. so that they
+	// can initialize RAM first and copy the kernel or something.
+	mov	hilo(CSYM(start_kernel)), r12
+	jmp	[r12]
+C_END(start)