From a6e13e31d5c34d59c28e908f3e51cf87bc82666f Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Thu, 29 Dec 2022 17:18:23 +0800 Subject: [PATCH] hw/char: riscv_htif: Support console output via proxy syscall 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 Reviewed-by: Daniel Henrique Barboza Reviewed-by: Alistair Francis Message-Id: <20221229091828.1945072-8-bmeng@tinylab.org> Signed-off-by: Alistair Francis --- 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);