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u-boot/drivers/serial/serial_sbi.c

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serial: Add a debug console using the RISC-V SBI interface The RISC-V SBI interface v0.1 provides a function for printing a character to the console. Even though SBI v0.1 functions are deprecated, the SBI console is quite useful for early debugging, because it works without any dcache, memory, or MMIO access in S mode. Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-09-12 15:56:09 +00:00
// SPDX-License-Identifier: GPL-2.0+
#include <debug_uart.h>
#include <asm/sbi.h>
risc-v: implement DBCN based debug console Use the DBCN SBI extension to implement a debug console. Make it the default for S-mode RISC-V. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2023-09-04 11:24:04 +00:00
#ifdef CONFIG_SBI_V01
serial: Add a debug console using the RISC-V SBI interface The RISC-V SBI interface v0.1 provides a function for printing a character to the console. Even though SBI v0.1 functions are deprecated, the SBI console is quite useful for early debugging, because it works without any dcache, memory, or MMIO access in S mode. Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-09-12 15:56:09 +00:00
static inline void _debug_uart_init(void)
{
}
static inline void _debug_uart_putc(int c)
{
if (CONFIG_IS_ENABLED(RISCV_SMODE))
sbi_console_putchar(c);
}
risc-v: implement DBCN based debug console Use the DBCN SBI extension to implement a debug console. Make it the default for S-mode RISC-V. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2023-09-04 11:24:04 +00:00
#else
static int sbi_dbcn_available;
static inline void _debug_uart_init(void)
{
if (CONFIG_IS_ENABLED(RISCV_SMODE))
sbi_dbcn_available = sbi_probe_extension(SBI_EXT_DBCN);
}
static inline void _debug_uart_putc(int ch)
{
if (CONFIG_IS_ENABLED(RISCV_SMODE) && sbi_dbcn_available)
sbi_dbcn_write_byte(ch);
}
#endif
serial: Add a debug console using the RISC-V SBI interface The RISC-V SBI interface v0.1 provides a function for printing a character to the console. Even though SBI v0.1 functions are deprecated, the SBI console is quite useful for early debugging, because it works without any dcache, memory, or MMIO access in S mode. Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-09-12 15:56:09 +00:00
DEBUG_UART_FUNCS
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