From c1a144d77a6ca3a14ba3c0fec30bc4fd20b3d817 Mon Sep 17 00:00:00 2001 From: Aurelien Jacquiot Date: Tue, 4 Oct 2011 11:00:02 -0400 Subject: C6X: early boot code Original port to early 2.6 kernel using TI COFF toolchain. Brought up to date by Mark Salter This patch provides the early boot code for C6X architecture. There is a 16 entry vector table which is used to direct reset and interrupt events. The vector table entries contain a small amount of code (maximum of 8 opcodes) which simply branches to the actual event handling code. The head.S code simply clears BSS, setups up a few control registers, and calls machine_init followed by start_kernel. The machine_init code in setup.c does the early flat tree parsing (memory, commandline, etc). At setup_arch time, the code does the usual memory setup and minimally scans the devicetree for any needed information. Signed-off-by: Aurelien Jacquiot Signed-off-by: Mark Salter Acked-by: Arnd Bergmann --- arch/c6x/kernel/head.S | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 arch/c6x/kernel/head.S (limited to 'arch/c6x/kernel/head.S') diff --git a/arch/c6x/kernel/head.S b/arch/c6x/kernel/head.S new file mode 100644 index 000000000000..133eab6edf6b --- /dev/null +++ b/arch/c6x/kernel/head.S @@ -0,0 +1,84 @@ +; +; Port on Texas Instruments TMS320C6x architecture +; +; Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated +; Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) +; +; 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. +; +#include +#include +#include + + __HEAD +ENTRY(_c_int00) + ;; Save magic and pointer + MV .S1 A4,A10 + MV .S2 B4,B10 + MVKL .S2 __bss_start,B5 + MVKH .S2 __bss_start,B5 + MVKL .S2 __bss_stop,B6 + MVKH .S2 __bss_stop,B6 + SUB .L2 B6,B5,B6 ; bss size + + ;; Set the stack pointer + MVKL .S2 current_ksp,B0 + MVKH .S2 current_ksp,B0 + LDW .D2T2 *B0,B15 + + ;; clear bss + SHR .S2 B6,3,B0 ; number of dwords to clear + ZERO .L2 B13 + ZERO .L2 B12 +bss_loop: + BDEC .S2 bss_loop,B0 + NOP 3 + CMPLT .L2 B0,0,B1 + [!B1] STDW .D2T2 B13:B12,*B5++[1] + + NOP 4 + AND .D2 ~7,B15,B15 + + ;; Clear GIE and PGIE + MVC .S2 CSR,B2 + CLR .S2 B2,0,1,B2 + MVC .S2 B2,CSR + MVC .S2 TSR,B2 + CLR .S2 B2,0,1,B2 + MVC .S2 B2,TSR + MVC .S2 ITSR,B2 + CLR .S2 B2,0,1,B2 + MVC .S2 B2,ITSR + MVC .S2 NTSR,B2 + CLR .S2 B2,0,1,B2 + MVC .S2 B2,NTSR + + ;; pass DTB pointer to machine_init (or zero if none) + MVKL .S1 OF_DT_HEADER,A0 + MVKH .S1 OF_DT_HEADER,A0 + CMPEQ .L1 A10,A0,A0 + [A0] MV .S1X B10,A4 + [!A0] MVK .S1 0,A4 + +#ifdef CONFIG_C6X_BIG_KERNEL + MVKL .S1 machine_init,A0 + MVKH .S1 machine_init,A0 + B .S2X A0 + ADDKPC .S2 0f,B3,4 +0: +#else + CALLP .S2 machine_init,B3 +#endif + + ;; Jump to Linux init +#ifdef CONFIG_C6X_BIG_KERNEL + MVKL .S1 start_kernel,A0 + MVKH .S1 start_kernel,A0 + B .S2X A0 +#else + B .S2 start_kernel +#endif + NOP 5 +L1: BNOP .S2 L1,5 -- cgit v1.2.1