Re: [Qemu-devel] [PATCH v2 20/22] mips_malta: update malta's pseudo-bootloader - replace JR with JALR

[Aurelien Jarno <aurelien@aurel32.net>]

On Wed, Jun 11, 2014 at 04:19:50PM +0100, Leon Alrae wrote:
> JR has been removed in R6 and now this instruction will cause Reserved
> Instruction Exception. Therefore use JALR with rd=0 which is equivalent to JR.
> 
> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
> ---
>  hw/mips/mips_malta.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
> index f4a7d47..72071c0 100644
> --- a/hw/mips/mips_malta.c
> +++ b/hw/mips/mips_malta.c
> @@ -694,12 +694,12 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base,
>      /* Jump to kernel code */
>      stl_p(p++, 0x3c1f0000 | ((kernel_entry >> 16) & 0xffff));    /* lui ra, high(kernel_entry) */
>      stl_p(p++, 0x37ff0000 | (kernel_entry & 0xffff));            /* ori ra, ra, low(kernel_entry) */
> -    stl_p(p++, 0x03e00008);                                      /* jr ra */
> +    stl_p(p++, 0x03e00009);                                      /* jalr ra */
>      stl_p(p++, 0x00000000);                                      /* nop */
>  
>      /* YAMON subroutines */
>      p = (uint32_t *) (base + 0x800);
> -    stl_p(p++, 0x03e00008);                                     /* jr ra */
> +    stl_p(p++, 0x03e00009);                                     /* jalr ra */
>      stl_p(p++, 0x24020000);                                     /* li v0,0 */
>     /* 808 YAMON print */
>      stl_p(p++, 0x03e06821);                                     /* move t5,ra */
> @@ -713,7 +713,7 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base,
>      stl_p(p++, 0x00000000);                                     /* nop */
>      stl_p(p++, 0x08000205);                                     /* j 814 */
>      stl_p(p++, 0x00000000);                                     /* nop */
> -    stl_p(p++, 0x01a00008);                                     /* jr t5 */
> +    stl_p(p++, 0x01a00009);                                     /* jalr t5 */
>      stl_p(p++, 0x01602021);                                     /* move a0,t3 */
>      /* 0x83c YAMON print_count */
>      stl_p(p++, 0x03e06821);                                     /* move t5,ra */
> @@ -727,7 +727,7 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base,
>      stl_p(p++, 0x258cffff);                                     /* addiu t4,t4,-1 */
>      stl_p(p++, 0x1580fffa);                                     /* bnez t4,84c */
>      stl_p(p++, 0x00000000);                                     /* nop */
> -    stl_p(p++, 0x01a00008);                                     /* jr t5 */
> +    stl_p(p++, 0x01a00009);                                     /* jalr t5 */
>      stl_p(p++, 0x01602021);                                     /* move a0,t3 */
>      /* 0x870 */
>      stl_p(p++, 0x3c08b800);                                     /* lui t0,0xb400 */
> @@ -737,7 +737,7 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base,
>      stl_p(p++, 0x31290040);                                     /* andi t1,t1,0x40 */
>      stl_p(p++, 0x1120fffc);                                     /* beqz t1,878 <outch+0x8> */
>      stl_p(p++, 0x00000000);                                     /* nop */
> -    stl_p(p++, 0x03e00008);                                     /* jr ra */
> +    stl_p(p++, 0x03e00009);                                     /* jalr ra */
>      stl_p(p++, 0xa1040000);                                     /* sb a0,0(t0) */
>  

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net