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| author | Ronald G. Minnich <rminnich@gmail.com> | 2016-11-12 07:31:16 -0800 |
|---|---|---|
| committer | Ronald G. Minnich <rminnich@gmail.com> | 2016-11-14 01:09:12 +0100 |
| commit | 3d302b03f46fa6ed5927cdc2ef9f53b9ce0262ae (patch) | |
| tree | 4d509bb2bbf0cdb62ba7cd3b035b22416511afdb | |
| parent | 42c1e43cb16b26925611335bdc97808dae745af5 (diff) | |
| download | coreboot-3d302b03f46fa6ed5927cdc2ef9f53b9ce0262ae.tar.xz | |
riscv: add a variable to control trap management
This variable can be set in a debugger (e.g. Spike)
to finely control which traps go to coreboot and
which go to the supervisor.
Change-Id: I292264c15f002c41cf8d278354d8f4c0efbd0895
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/17404
Tested-by: build bot (Jenkins)
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
| -rw-r--r-- | src/arch/riscv/virtual_memory.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/src/arch/riscv/virtual_memory.c b/src/arch/riscv/virtual_memory.c index 999d73cec8..6d93bd0def 100644 --- a/src/arch/riscv/virtual_memory.c +++ b/src/arch/riscv/virtual_memory.c @@ -23,6 +23,21 @@ #include <vm.h> #include <symbols.h> +/* Delegate controls which traps are delegated to the payload. If you + * wish to temporarily disable some or all delegation you can, in a + * debugger, set it to a different value (e.g. 0 to have all traps go + * to M-mode). In practice, this variable has been a lifesaver. It is + * still not quite determined which delegation might by unallowed by + * the spec so for now we enumerate and set them all. */ +static int delegate = 0 + | (1 << CAUSE_MISALIGNED_FETCH) + | (1 << CAUSE_FAULT_FETCH) + | (1 << CAUSE_ILLEGAL_INSTRUCTION) + | (1 << CAUSE_BREAKPOINT) + | (1 << CAUSE_FAULT_LOAD) + | (1 << CAUSE_FAULT_STORE) + | (1 << CAUSE_USER_ECALL) + ; pte_t* root_page_table; /* Indent the following text by 2*level spaces */ @@ -223,16 +238,7 @@ void mstatus_init(void) clear_csr(mip, MIP_MSIP); set_csr(mie, MIP_MSIP); - /* Configure which exception causes are delegated to supervisor mode */ - set_csr(medeleg, (1 << CAUSE_MISALIGNED_FETCH) - | (1 << CAUSE_FAULT_FETCH) - | (1 << CAUSE_ILLEGAL_INSTRUCTION) - | (1 << CAUSE_BREAKPOINT) - | (1 << CAUSE_FAULT_LOAD) - | (1 << CAUSE_FAULT_STORE) - | (1 << CAUSE_USER_ECALL) - ); - + set_csr(medeleg, delegate); /* Enable all user/supervisor-mode counters */ /* We'll turn these on once lowrisc gets their bitstream up to |