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allowed for vectored and unvectored interrupts in trap handlers

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This commit is contained in:
Kip Macsai-Goren 2022-02-25 22:37:11 +00:00
parent ac03a95aeb
commit 2da39c7052
1 changed files with 46 additions and 7 deletions
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53
tests/wally-riscv-arch-test/riscv-test-suite/rv64i_m/privilege/src/WALLY-TEST-LIB-64.h
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@ -55,12 +55,15 @@ RVTEST_CODE_BEGIN
.endm
.macro TRAP_HANDLER MODE // default to vectored tests
.macro TRAP_HANDLER MODE, VECTORED=1 // default to vectored tests
// Set up the exception Handler, keeping the original handler in x4.
// trap handler setup
la x1, trap_handler_\MODE\()
.if (\VECTORED == 1)
ori x1, x1, 0x1 // set mode field of tvec to 1, forcing vectored interrupts
.endif
.if (\MODE\() == m)
csrrw x4, \MODE\()tvec, x1 // x4 reserved for "default" trap handler address that needs to be restored before halting this test.
.else
@ -71,7 +74,8 @@ RVTEST_CODE_BEGIN
li a1, 0
li a2, 0 // reset trap handler inputs to zero
j trap_handler_end_\MODE\()
j trap_handler_end_\MODE\() // skip the trap handler when it is being defined.
// ---------------------------------------------------------------------------------------------
// General traps Handler
//
@ -106,9 +110,25 @@ RVTEST_CODE_BEGIN
//
// --------------------------------------------------------------------------------------------
.align 2
trap_handler_\MODE\():
// The processor is always in machine mode when a trap takes us here
j trap_unvectored_\MODE\() // for the unvectored implimentation: jump past this table of addresses into the actual handler
// *** ASSUMES that a cause value of 0 for an interrupt is unimplemented
// otherwise, a vectored interrupt handler should jump to trap_handler_\MODE\() + 4 * Interrupt cause code
.4byte s_soft_interrupt_\MODE\() // 1: instruction access fault // the zero spot is taken up by the instruction to skip this table.
.4byte segfault_\MODE\() // 2: reserved
.4byte m_soft_interrupt_\MODE\() // 3: breakpoint
.4byte segfault_\MODE\() // 4: reserved
.4byte s_time_interrupt_\MODE\() // 5: load access fault
.4byte segfault_\MODE\() // 6: reserved
.4byte m_time_interrupt_\MODE\() // 7: store access fault
.4byte segfault_\MODE\() // 8: reserved
.4byte s_ext_interrupt_\MODE\() // 9: ecall from S-mode
.4byte segfault_\MODE\() // 10: reserved
.4byte m_ext_interrupt_\MODE\() // 11: ecall from M-mode
// 12 through >=16 are reserved or designated for platform use
trap_unvectored_\MODE\():
// save registers on stack before using
sd x1, -8(sp)
sd x5, -16(sp)
@ -126,7 +146,7 @@ trap_handler_\MODE\():
bnez x5, trapreturn_\MODE\() // return from interrupt
// Other trap handling is specified in the vector Table
slli x1, x1, 3 // multiply cause by 8 to get offset in vector Table
la x5, trap_handler_vector_table_\MODE\()
la x5, exception_vector_table_\MODE\()
add x5, x5, x1 // compute address of vector in Table
ld x5, 0(x5) // fectch address of handler from vector Table
jr x5 // and jump to the handler
@ -248,13 +268,32 @@ accessfault_\MODE\():
// *** What do I have to do here?
j trapreturn_\MODE\()
s_soft_interrupt_\MODE\(): // these labels are here to make sure the code compiles, but don't actually do anything yet
j trapreturn_\MODE\()
m_soft_interrupt_\MODE\():
j trapreturn_\MODE\()
s_time_interrupt_\MODE\():
j trapreturn_\MODE\()
m_time_interrupt_\MODE\():
j trapreturn_\MODE\()
s_ext_interrupt_\MODE\():
j trapreturn_\MODE\()
m_ext_interrupt_\MODE\():
j trapreturn_\MODE\()
// Table of trap behavior
// lists what to do on each exception (not interrupts)
// unexpected exceptions should cause segfaults for easy detection
// Expected exceptions should increment the EPC to the next instruction and return
.align 3 // aligns this data table to an 8 byte boundary
trap_handler_vector_table_\MODE\():
exception_vector_table_\MODE\():
.8byte segfault_\MODE\() // 0: instruction address misaligned
.8byte instrfault_\MODE\() // 1: instruction access fault
.8byte illegalinstr_\MODE\() // 2: illegal instruction