diff options
| -rw-r--r-- | include/sbi_utils/serial/semihosting.h | 47 | ||||
| -rw-r--r-- | lib/utils/serial/Kconfig | 4 | ||||
| -rw-r--r-- | lib/utils/serial/objects.mk | 1 | ||||
| -rw-r--r-- | lib/utils/serial/semihosting.c | 178 | ||||
| -rw-r--r-- | platform/generic/configs/defconfig | 1 | ||||
| -rw-r--r-- | platform/generic/platform.c | 11 |
6 files changed, 241 insertions, 1 deletions
diff --git a/include/sbi_utils/serial/semihosting.h b/include/sbi_utils/serial/semihosting.h new file mode 100644 index 0000000..8cc4a86 --- /dev/null +++ b/include/sbi_utils/serial/semihosting.h @@ -0,0 +1,47 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 Ventana Micro Systems Inc. + * + * Authors: + * Anup Patel <apatel@ventanamicro.com> + * Kautuk Consul <kconsul@ventanamicro.com> + */ + +#ifndef __SERIAL_SEMIHOSTING_H__ +#define __SERIAL_SEMIHOSTING_H__ + +#include <sbi/sbi_types.h> + +/** + * enum semihosting_open_mode - Numeric file modes for use with semihosting_open() + * MODE_READ: 'r' + * MODE_BINARY: 'b' + * MODE_PLUS: '+' + * MODE_WRITE: 'w' + * MODE_APPEND: 'a' + * + * These modes represent the mode string used by fopen(3) in a form which can + * be passed to semihosting_open(). These do NOT correspond directly to %O_RDONLY, + * %O_CREAT, etc; see fopen(3) for details. In particular, @MODE_PLUS + * effectively results in adding %O_RDWR, and @MODE_WRITE will add %O_TRUNC. + * For compatibility, @MODE_BINARY should be added when opening non-text files + * (such as images). + */ +enum semihosting_open_mode { + MODE_READ = 0x0, + MODE_BINARY = 0x1, + MODE_PLUS = 0x2, + MODE_WRITE = 0x4, + MODE_APPEND = 0x8, +}; + +#ifdef CONFIG_SERIAL_SEMIHOSTING +int semihosting_init(void); +int semihosting_enabled(void); +#else +static inline int semihosting_init(void) { return SBI_ENODEV; } +static inline int semihosting_enabled(void) { return 0; } +#endif + +#endif diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig index 6e425f2..da549a7 100644 --- a/lib/utils/serial/Kconfig +++ b/lib/utils/serial/Kconfig @@ -79,4 +79,8 @@ config SERIAL_XILINX_UARTLITE bool "Xilinx UART Lite support" default n +config SERIAL_SEMIHOSTING + bool "Semihosting support" + default n + endmenu diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk index efb1d9e..98f3f9a 100644 --- a/lib/utils/serial/objects.mk +++ b/lib/utils/serial/objects.mk @@ -41,3 +41,4 @@ libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o libsbiutils-objs-$(CONFIG_SERIAL_LITEX) += serial/litex-uart.o libsbiutils-objs-$(CONFIG_SERIAL_UART8250) += serial/uart8250.o libsbiutils-objs-$(CONFIG_SERIAL_XILINX_UARTLITE) += serial/xlnx-uartlite.o +libsbiutils-objs-$(CONFIG_SERIAL_SEMIHOSTING) += serial/semihosting.o diff --git a/lib/utils/serial/semihosting.c b/lib/utils/serial/semihosting.c new file mode 100644 index 0000000..5012fa1 --- /dev/null +++ b/lib/utils/serial/semihosting.c @@ -0,0 +1,178 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 Ventana Micro Systems Inc. + * + * Authors: + * Anup Patel <apatel@ventanamicro.com> + * Kautuk Consul <kconsul@ventanamicro.com> + */ + +#include <sbi/sbi_console.h> +#include <sbi/sbi_string.h> +#include <sbi/sbi_error.h> +#include <sbi_utils/serial/semihosting.h> + +#define SYSOPEN 0x01 +#define SYSWRITEC 0x03 +#define SYSREAD 0x06 +#define SYSREADC 0x07 +#define SYSERRNO 0x13 + +static long semihosting_trap(int sysnum, void *addr) +{ + register int ret asm ("a0") = sysnum; + register void *param0 asm ("a1") = addr; + + asm volatile ( + " .align 4\n" + " .option push\n" + " .option norvc\n" + + " slli zero, zero, 0x1f\n" + " ebreak\n" + " srai zero, zero, 7\n" + + " .option pop\n" + : "+r" (ret) : "r" (param0) : "memory"); + + return ret; +} + +static bool _semihosting_enabled = true; +static bool try_semihosting = true; + +bool semihosting_enabled(void) +{ + register int ret asm ("a0") = SYSERRNO; + register void *param0 asm ("a1") = NULL; + unsigned long tmp = 0; + + if (!try_semihosting) + return _semihosting_enabled; + + asm volatile ( + " .align 4\n" + " .option push\n" + " .option norvc\n" + + " j _semihost_test_vector_next\n" + " .align 4\n" + "_semihost_test_vector:\n" + " csrr %[en], mepc\n" + " addi %[en], %[en], 4\n" + " csrw mepc, %[en]\n" + " add %[en], zero, zero\n" + " mret\n" + "_semihost_test_vector_next:\n" + + " la %[tmp], _semihost_test_vector\n" + " csrrw %[tmp], mtvec, %[tmp]\n" + " .align 4\n" + " slli zero, zero, 0x1f\n" + " ebreak\n" + " srai zero, zero, 7\n" + " csrw mtvec, %[tmp]\n" + + " .option pop\n" + : [tmp] "+r" (tmp), [en] "+r" (_semihosting_enabled), + [ret] "+r" (ret) + : "r" (param0) : "memory"); + + try_semihosting = false; + return _semihosting_enabled; +} + +static int semihosting_errno(void) +{ + long ret = semihosting_trap(SYSERRNO, NULL); + + if (ret > 0) + return -ret; + return SBI_EIO; +} + +static int semihosting_infd = SBI_ENODEV; + +static long semihosting_open(const char *fname, enum semihosting_open_mode mode) +{ + long fd; + struct semihosting_open_s { + const char *fname; + unsigned long mode; + size_t len; + } open; + + open.fname = fname; + open.len = sbi_strlen(fname); + open.mode = mode; + + /* Open the file on the host */ + fd = semihosting_trap(SYSOPEN, &open); + if (fd == -1) + return semihosting_errno(); + return fd; +} + +/** + * struct semihosting_rdwr_s - Arguments for read and write + * @fd: A file descriptor returned from semihosting_open() + * @memp: Pointer to a buffer of memory of at least @len bytes + * @len: The number of bytes to read or write + */ +struct semihosting_rdwr_s { + long fd; + void *memp; + size_t len; +}; + +static long semihosting_read(long fd, void *memp, size_t len) +{ + long ret; + struct semihosting_rdwr_s read; + + read.fd = fd; + read.memp = memp; + read.len = len; + + ret = semihosting_trap(SYSREAD, &read); + if (ret < 0) + return semihosting_errno(); + return len - ret; +} + +/* clang-format on */ + +static void semihosting_putc(char ch) +{ + semihosting_trap(SYSWRITEC, &ch); +} + +static int semihosting_getc(void) +{ + char ch = 0; + int ret; + + if (semihosting_infd < 0) { + ch = semihosting_trap(SYSREADC, NULL); + ret = ch > -1 ? ch : -1; + } else + ret = semihosting_read(semihosting_infd, &ch, 1) > 0 ? ch : -1; + + return ret; +} + +static struct sbi_console_device semihosting_console = { + .name = "semihosting", + .console_putc = semihosting_putc, + .console_getc = semihosting_getc +}; + +int semihosting_init(void) +{ + semihosting_infd = semihosting_open(":tt", MODE_READ); + + sbi_console_set_device(&semihosting_console); + + return 0; +} diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig index e324173..c95b7fa 100644 --- a/platform/generic/configs/defconfig +++ b/platform/generic/configs/defconfig @@ -28,3 +28,4 @@ CONFIG_FDT_SERIAL_UART8250=y CONFIG_FDT_SERIAL_XILINX_UARTLITE=y CONFIG_FDT_TIMER=y CONFIG_FDT_TIMER_MTIMER=y +CONFIG_SERIAL_SEMIHOSTING=y diff --git a/platform/generic/platform.c b/platform/generic/platform.c index cc3620f..bf51aba 100644 --- a/platform/generic/platform.c +++ b/platform/generic/platform.c @@ -23,6 +23,7 @@ #include <sbi_utils/timer/fdt_timer.h> #include <sbi_utils/ipi/fdt_ipi.h> #include <sbi_utils/reset/fdt_reset.h> +#include <sbi_utils/serial/semihosting.h> /* List of platform override modules generated at compile time */ extern const struct platform_override *platform_override_modules[]; @@ -242,6 +243,14 @@ static uint64_t generic_pmu_xlate_to_mhpmevent(uint32_t event_idx, return evt_val; } +static int generic_console_init(void) +{ + if (semihosting_enabled()) + return semihosting_init(); + else + return fdt_serial_init(); +} + const struct sbi_platform_operations platform_ops = { .nascent_init = generic_nascent_init, .early_init = generic_early_init, @@ -249,7 +258,7 @@ const struct sbi_platform_operations platform_ops = { .early_exit = generic_early_exit, .final_exit = generic_final_exit, .domains_init = generic_domains_init, - .console_init = fdt_serial_init, + .console_init = generic_console_init, .irqchip_init = fdt_irqchip_init, .irqchip_exit = fdt_irqchip_exit, .ipi_init = fdt_ipi_init, |