From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anup Patel Date: Thu, 24 Nov 2022 18:59:04 +0530 Subject: [PATCH v3 4/6] lib: sbi: Implement SBI debug console extension In-Reply-To: <20221124132906.257732-1-apatel@ventanamicro.com> References: <20221124132906.257732-1-apatel@ventanamicro.com> Message-ID: <20221124132906.257732-5-apatel@ventanamicro.com> List-Id: To: opensbi@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit We implement SBI debug console extension as one of the replacement SBI extensions. This extension is only available when OpenSBI platform provides a console device to generic library. Signed-off-by: Anup Patel --- lib/sbi/Kconfig | 4 +++ lib/sbi/objects.mk | 3 ++ lib/sbi/sbi_ecall_dbcn.c | 62 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+) create mode 100644 lib/sbi/sbi_ecall_dbcn.c diff --git a/lib/sbi/Kconfig b/lib/sbi/Kconfig index df74bba..ef6728b 100644 --- a/lib/sbi/Kconfig +++ b/lib/sbi/Kconfig @@ -26,6 +26,10 @@ config SBI_ECALL_PMU bool "Performance Monitoring Unit extension" default y +config SBI_ECALL_DBCN + bool "Debug Console extension" + default y + config SBI_ECALL_LEGACY bool "SBI v0.1 legacy extensions" default y diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk index c774ebb..319f38d 100644 --- a/lib/sbi/objects.mk +++ b/lib/sbi/objects.mk @@ -37,6 +37,9 @@ libsbi-objs-$(CONFIG_SBI_ECALL_SRST) += sbi_ecall_srst.o carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_PMU) += ecall_pmu libsbi-objs-$(CONFIG_SBI_ECALL_PMU) += sbi_ecall_pmu.o +carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_DBCN) += ecall_dbcn +libsbi-objs-$(CONFIG_SBI_ECALL_DBCN) += sbi_ecall_dbcn.o + carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_LEGACY) += ecall_legacy libsbi-objs-$(CONFIG_SBI_ECALL_LEGACY) += sbi_ecall_legacy.o diff --git a/lib/sbi/sbi_ecall_dbcn.c b/lib/sbi/sbi_ecall_dbcn.c new file mode 100644 index 0000000..19ac021 --- /dev/null +++ b/lib/sbi/sbi_ecall_dbcn.c @@ -0,0 +1,62 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 Ventana Micro Systems Inc. + * + * Authors: + * Anup Patel + */ + +#include +#include +#include +#include +#include +#include +#include + +static int sbi_ecall_dbcn_handler(unsigned long extid, unsigned long funcid, + const struct sbi_trap_regs *regs, + unsigned long *out_val, + struct sbi_trap_info *out_trap) +{ + ulong smode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >> + MSTATUS_MPP_SHIFT; + + if (funcid == SBI_EXT_DBCN_CONSOLE_PUTS) { + /* + * On RV32, the M-mode can only access the first 4GB of + * the physical address space because M-mode does not have + * MMU to access full 34-bit physical address space. + * + * Based on above, we simply fail if the upper 32bits of + * the physical address (i.e. a2 register) is non-zero on + * RV32. + */ +#if __riscv_xlen == 32 + if (regs->a2) + return SBI_ERR_FAILED; +#endif + if (!sbi_domain_check_addr_range(sbi_domain_thishart_ptr(), + regs->a1, regs->a0, smode, + SBI_DOMAIN_READ|SBI_DOMAIN_WRITE)) + return SBI_EINVALID_ADDR; + sbi_nputs((const char *)regs->a1, regs->a0); + return 0; + } + + return SBI_ENOTSUPP; +} + +static int sbi_ecall_dbcn_probe(unsigned long extid, unsigned long *out_val) +{ + *out_val = (sbi_console_get_device()) ? 1 : 0; + return 0; +} + +struct sbi_ecall_extension ecall_dbcn = { + .extid_start = SBI_EXT_DBCN, + .extid_end = SBI_EXT_DBCN, + .handle = sbi_ecall_dbcn_handler, + .probe = sbi_ecall_dbcn_probe, +}; -- 2.34.1