diff options
| author | Aurelien Jacquiot <a-jacquiot@ti.com> | 2011-10-04 11:00:02 -0400 |
|---|---|---|
| committer | Mark Salter <msalter@redhat.com> | 2011-10-06 19:47:28 -0400 |
| commit | c1a144d77a6ca3a14ba3c0fec30bc4fd20b3d817 (patch) | |
| tree | e5a761211a22a90ca2eb1c933d2b3539c6888831 /arch/c6x/kernel/head.S | |
| parent | c278400c52c14203894c5dc0d63cf385239d8329 (diff) | |
C6X: early boot code
Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
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 <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/c6x/kernel/head.S')
| -rw-r--r-- | arch/c6x/kernel/head.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/c6x/kernel/head.S b/arch/c6x/kernel/head.S new file mode 100644 index 00000000000..133eab6edf6 --- /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 <linux/linkage.h> +#include <linux/of_fdt.h> +#include <asm/asm-offsets.h> + + __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 |