On Sat, 19 Jun 2021 17:20:05 +0800
Icenowy Zheng <icen...@aosc.io> wrote:
> There's now a sun20i family in sunxi, which uses RISC-V CPU.
>
> Add support for making eGON.BT0 image for RISC-V.
>
> Signed-off-by: Icenowy Zheng <icen...@aosc.io>
Compared against the RISC-V manual.
Reviewed-by: Andre Przywara <andre.przyw...@arm.com>
Cheers,
Andre
> ---
> Changes in v2:
> - Removed changes that should belong to the previous patch in v1.
>
> tools/sunxi_egon.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/tools/sunxi_egon.c b/tools/sunxi_egon.c
> index 062c9bc151..836e99a6e6 100644
> --- a/tools/sunxi_egon.c
> +++ b/tools/sunxi_egon.c
> @@ -29,6 +29,7 @@ static int egon_check_params(struct image_tool_params
> *params)
> */
> switch (arch) {
> case IH_ARCH_ARM:
> + case IH_ARCH_RISCV:
> break;
> default:
> return EXIT_FAILURE;
> @@ -60,6 +61,10 @@ static int egon_verify_header(unsigned char *ptr, int
> image_size,
> if ((le32_to_cpu(header->b_instruction) & 0xff000000) !=
> 0xea000000)
> return EXIT_FAILURE;
> break;
> + case IH_ARCH_RISCV:
> + if ((le32_to_cpu(header->b_instruction) & 0x00000fff) !=
> 0x0000006f)
> + return EXIT_FAILURE;
> + break;
> default:
> return EXIT_FAILURE; /* Unknown architecture */
> }
> @@ -128,6 +133,24 @@ static void egon_set_header(void *buf, struct stat
> *sbuf, int infd,
> value = 0xea000000 | (sizeof(struct boot_file_head) / 4 - 2);
> header->b_instruction = cpu_to_le32(value);
> break;
> + case IH_ARCH_RISCV:
> + /*
> + * Generate a RISC-V JAL instruction with rd=x0
> + * (pseudo instruction J, jump without side effects).
> + *
> + * The following weird bit operation maps imm[20]
> + * to inst[31], imm[10:1] to inst[30:21],
> + * imm[11] to inst[20], imm[19:12] to inst[19:12],
> + * and imm[0] is dropped (because 1-byte RISC-V instruction
> + * is not allowed).
> + */
> + value = 0x0000006f |
> + ((sizeof(struct boot_file_head) & 0x00100000) << 11) |
> + ((sizeof(struct boot_file_head) & 0x000007fe) << 20) |
> + ((sizeof(struct boot_file_head) & 0x00000800) << 9) |
> + ((sizeof(struct boot_file_head) & 0x000ff000) << 0);
> + header->b_instruction = cpu_to_le32(value);
> + break;
> }
>
> memcpy(header->magic, BOOT0_MAGIC, sizeof(header->magic));
