On Tue, Dec 27, 2022 at 4:49 PM Bin Meng <bm...@tinylab.org> wrote:
>
> At present the HTIF proxy syscall is unsupported. On RV32, only
> device 0 is supported so there is no console device for RV32.
> The only way to implement console funtionality on RV32 is to
> support the SYS_WRITE syscall.
>
> With this commit, the Spike machine is able to boot the 32-bit
> OpenSBI generic image.
>
> Signed-off-by: Bin Meng <bm...@tinylab.org>
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
>
> hw/char/riscv_htif.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/hw/char/riscv_htif.c b/hw/char/riscv_htif.c
> index 3bb0a37a3e..1477fc0090 100644
> --- a/hw/char/riscv_htif.c
> +++ b/hw/char/riscv_htif.c
> @@ -48,6 +48,9 @@
> #define HTIF_CONSOLE_CMD_GETC 0
> #define HTIF_CONSOLE_CMD_PUTC 1
>
> +/* PK system call number */
> +#define PK_SYS_WRITE 64
> +
> static uint64_t fromhost_addr, tohost_addr;
> static int address_symbol_set;
>
> @@ -165,7 +168,19 @@ static void htif_handle_tohost_write(HTIFState *s,
> uint64_t val_written)
> int exit_code = payload >> 1;
> exit(exit_code);
> } else {
> - qemu_log_mask(LOG_UNIMP, "pk syscall proxy not supported\n");
> + uint64_t syscall[8];
> + cpu_physical_memory_read(payload, syscall, sizeof(syscall));
> + if (syscall[0] == PK_SYS_WRITE &&
> + syscall[1] == HTIF_DEV_CONSOLE &&
> + syscall[3] == HTIF_CONSOLE_CMD_PUTC) {
> + uint8_t ch;
> + cpu_physical_memory_read(syscall[2], &ch, 1);
> + qemu_chr_fe_write(&s->chr, &ch, 1);
> + resp = 0x100 | (uint8_t)payload;
> + } else {
> + qemu_log_mask(LOG_UNIMP,
> + "pk syscall proxy not supported\n");
> + }
> }
> } else {
> qemu_log("HTIF device %d: unknown command\n", device);
> --
> 2.34.1
>
>
