RISC-V Debug specification includes Sdtrig ISA extension
which describes Trigger Module. Triggers can cause
a breakpoint exception or trace action without execution
of a special instruction. They can be used to implement
hardware breakpoints and watchpoints for native debugging.
The SBI Debut Trigger extension (Draft v6) can be found at:
https://lists.riscv.org/g/tech-debug/topic/99825362#1302
This patch is an initial implementation of SBI Debug
Trigger Extension (Draft v6) in OpenSBI.
The following features are supported:
* mcontrol, mcontrol6 triggers
* Breakpoint and trace actions
NOTE: Chained triggers are not supported
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Detect if debug triggers, sdtrig extension, is supported
by the CPU. The support is detected by access traps and
ISA string parsing.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This patch introduces Mcontrol and M6 control register
encodings along with macros to manipulate them.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Introduce cpu_to_lle and lle_to_cpu macros which invoke
correct word length cpu_to_le<64/32> conversion based on
__riscv_xlen.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
With Smepmp enabled, it is necessary for shared memory from
S/U mode to be mapped/unmapped before and after read/write
of the memory region. This patch maps the debug console
shared memory before accessing it.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
When Smepmp is enabled, M-mode will need to map/unmap the
shared memory before it can read/write to it. This patch
adds functions to create dynamic short-lived mappings.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
- If Smepmp is enabled, the access flags of an entry are determined based on
truth table defined in Smepmp.
- First PMP entry (index 0) is reserved.
- Existing boot PMP entries start from index 1.
- Since enabling Smepmp revokes the access privileges of the M-mode software
on S/U-mode region, first PMP entry is used to map/unmap the shared memory
between M and S/U-mode. This allows a temporary access window for the M-mode
software to read/write to S/U-mode memory region.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Configure PMP at last when all other initializations have been done.
Because if SMEPMP is detected, M-mode access to the S/U space will be
rescinded.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Since pmp entries have implicit priority on index, previous entries will
deny access to SU on M-mode region. Also, M-mode will not have access to
SU region while previous entries will allow access to M-mode regions.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
- Add function to parse ISA string in FDT.
- Set Smepmp feature bit in extensions if "smepmp" string is found in ISA string.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Smepmp specification defines a truth table based on which the access is allowed to
different modes. This patch adds different flags based on this truth table.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
- Add a function to disable a given PMP entry.
- Add a function to check if a given entry is disabled.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
In commit 230278dcf, RX and RW regions were marked separately.
When the RW region grows (e.g. with more harts) and it isn't a
power-of-two, sbi_domain_memregion_init will upgrade the region
to the next power-of-two. This will make RX and RW both start
at the same base address, like so (with 64 harts):
Domain0 Region01 : 0x0000000080000000-0x000000008001ffff M: (R,X) S/U: ()
Domain0 Region02 : 0x0000000080000000-0x00000000800fffff M: (R,W) S/U: ()
This doesn't break the permission enforcement because of static
priorities in PMP but makes the kernel complain about the regions
overlapping each other. Like so:
[ 0.000000] OF: reserved mem: OVERLAP DETECTED!
[ 0.000000] mmode_resv0@80000000 (0x0000000080000000--0x0000000080020000) \
overlaps with mmode_resv1@80000000 (0x0000000080000000--0x0000000080100000)
To fix this warning, among the multiple regions having same base
address but different sizes, add only the largest region as reserved
region during fdt fixup.
Fixes: 230278dcf (lib: sbi: Add separate entries for firmware RX and RW regions)
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Add two entries for firmware in the root domain:
1. TEXT: fw_start to _fw_rw_offset with RX permissions
2. DATA: _fw_rw_offset to fw_size with RW permissions
These permissions are still not enforced from M-mode but lay
the ground work for enforcing them for M-mode. SU-mode don't
have any access to these regions.
Sample output:
Domain0 Region01 : 0x0000000080000000-0x000000008001ffff M: (R,X) S/U: ()
Domain0 Region02 : 0x0000000080020000-0x000000008003ffff M: (R,W) S/U: ()
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Print the RW section offset when firmware base and size is
being printed.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Add the RW section offset, provided by _fw_rw_offset symbol,
to the scratch structure. This will be used to program
separate pmp entry for RW section.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Currently, the dynsym and reladyn sections are under RW data.
They are moved to the Read-only/Executable region.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Split the RO/RX and RW sections so that they can have
independent pmp entries with required permissions. The
split size is ensured to be a power-of-2 as required by
pmp.
_fw_rw_offset symbol marks the beginning of the data
section.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Updated the various permissions bits available for domains
defined in DT node and restrictions on them.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
The M-mode regions can only be added to the root domain. The non-root
domains shouldn't be able to add them from FDT.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
With the finer permission semantics, the region access
permissions must be displayed separately for M and SU mode.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Use the fine grained permission bits to decide if the region
permissions are to be enforced on all modes. Also use the new
permission bits for deciding on R/W/X bits in pmpcfg register.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Split the permissions for M-mode and SU-mode. This would
help if different sections of OpenSBI need to be given
different permissions and if M-mode has different permisssions
than the SU-mode over a region.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Not all systems have bash at a fixed location like /bin/bash.
FreeBSD, for example, would typically have it at /usr/local/bin/bash.
When building OpenSBI on freebsd system, the build breaks.
Its advisable to use: #!/usr/bin/env bash
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
As per section 3.7.2 of RISC-V Privileged Specification,
PMP settings must be synchronized with the virtual memory
system after PMP settings have been written.
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
