diff options
| author | James Hogan <james.hogan@imgtec.com> | 2012-09-21 17:38:15 +0100 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2013-03-02 20:09:17 +0000 |
| commit | 85d9d7a9206631abd1030cd69ebb1c45f4a01037 (patch) | |
| tree | 04041c1a8998b8bf4bd5d91bf4c157fca6164d19 /arch/metag/kernel/head.S | |
| parent | 87aa1328f23a6bec15115af4d815e9c378557ef6 (diff) | |
metag: Boot
Add boot code for metag. Due to the multi-threaded nature of Meta it is
not uncommon for an RTOS or bare metal application to be started on
other hardware threads by the bootloader. Since there is a single MMU
switch which affects all threads, the MMU is traditionally configured by
the bootloader prior to starting Linux. The bootloader passes a
structure to Linux which among other things contains information about
memory regions which have been mapped. Linux then assumes control of the
local heap memory region.
A kernel arguments string pointer or a flattened device tree pointer can
be provided in the third argument.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Diffstat (limited to 'arch/metag/kernel/head.S')
| -rw-r--r-- | arch/metag/kernel/head.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/metag/kernel/head.S b/arch/metag/kernel/head.S new file mode 100644 index 000000000000..8b1388663892 --- /dev/null +++ b/arch/metag/kernel/head.S @@ -0,0 +1,45 @@ + ! Copyright 2005,2006,2007,2009 Imagination Technologies + +#include <linux/init.h> +#include <generated/asm-offsets.h> +#undef __exit + + __HEAD + ! Setup the stack and get going into _metag_start_kernel + .global __start + .type __start,function +__start: + ! D1Ar1 contains pTBI (ISTAT) + ! D0Ar2 contains pTBI + ! D1Ar3 contains __pTBISegs + ! D0Ar4 contains kernel arglist pointer + + MOVT D0Re0,#HI(___pTBIs) + ADD D0Re0,D0Re0,#LO(___pTBIs) + SETL [D0Re0],D0Ar2,D1Ar1 + MOVT D0Re0,#HI(___pTBISegs) + ADD D0Re0,D0Re0,#LO(___pTBISegs) + SETD [D0Re0],D1Ar3 + MOV A0FrP,#0 + MOV D0Re0,#0 + MOV D1Re0,#0 + MOV D1Ar3,#0 + MOV D1Ar1,D0Ar4 !Store kernel boot params + MOV D1Ar5,#0 + MOV D0Ar6,#0 +#ifdef CONFIG_METAG_DSP + MOV D0.8,#0 +#endif + MOVT A0StP,#HI(_init_thread_union) + ADD A0StP,A0StP,#LO(_init_thread_union) + ADD A0StP,A0StP,#THREAD_INFO_SIZE + MOVT D1RtP,#HI(_metag_start_kernel) + CALL D1RtP,#LO(_metag_start_kernel) + .size __start,.-__start + + !! Needed by TBX + .global __exit + .type __exit,function +__exit: + XOR TXENABLE,D0Re0,D0Re0 + .size __exit,.-__exit |