--- /dev/null
+# Recursive make is bad, but in this case we're cross compiling which is a
+# pretty unusual use case.
+
+CC = $(RISCV)/bin/riscv64-unknown-elf-gcc
+OBJCOPY = $(RISCV)/bin/riscv64-unknown-elf-objcopy
+
+%.o: %.S
+ $(CC) -c $<
+
+debug_rom.h: debug_rom.raw
+ xxd -i $^ | sed "s/^unsigned/static const unsigned/" > $@
+
+debug_rom.raw: debug_rom
+ $(OBJCOPY) -O binary --only-section .text debug_rom debug_rom.raw
+
+debug_rom: debug_rom.o
+ $(CC) -nostdlib -nostartfiles -Tlink.ld -o $@ $^
+
+clean:
+ rm -f debug_rom debug_rom.o debug_rom.raw debug_rom.h
--- /dev/null
+# This code should be functional. Doesn't have to be optimal.
+# I'm writing it to prove that it can be done.
+
+# TODO: Update these constants once they're finalized in the doc.
+
+#define DCSR 0x790
+#define DCSR_CAUSE_DEBINT 3
+#define DCSR_HALT_OFFSET 3
+#define DCSR_DEBUGINT_OFFSET 10
+
+#define DSCRATCH 0x792
+
+#define MCPUID 0xf00
+#define MHARTID 0xf10
+
+#define DEBUG_RAM 0x400
+#define DEBUG_RAM_SIZE 64
+
+#define SETHALTNOT 0x100
+#define CLEARHALTNOT 0x104
+#define CLEARDEBINT 0x108
+
+ .global entry
+ .global resume
+
+ # Automatically called when Debug Mode is first entered.
+entry: j _entry
+ # Should be called by Debug RAM code that has finished execution and
+ # wants to return to Debug Mode.
+resume:
+ # Clear debug interrupt.
+clear_debint:
+ csrr s1, MHARTID
+ sw s1, CLEARDEBINT(zero)
+clear_debint_loop:
+ csrr s1, DCSR
+ andi s1, s1, (1<<DCSR_DEBUGINT_OFFSET)
+ bnez s1, wait_for_interrupt
+
+ # Restore s1.
+ csrr s1, MCPUID
+ bltz s1, restore_not_32
+restore_32:
+ lw s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
+ j check_halt
+restore_not_32:
+ slli s1, s1, 1
+ bltz s1, restore_128
+restore_64:
+ ld s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 8)(zero)
+ j check_halt
+restore_128:
+ nop #lq s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 16)(zero)
+
+check_halt:
+ csrr s0, DCSR
+ andi s0, s0, (1<<DCSR_HALT_OFFSET)
+ beqz s0, exit
+ j wait_for_interrupt
+
+exit:
+ # Restore s0.
+ csrr s0, DSCRATCH
+ eret
+
+
+_entry:
+ # Save s0 in DSCRATCH
+ csrw DSCRATCH, s0
+
+ # Check why we're here
+ csrr s0, DCSR
+ # cause is in bits 2:0 of dcsr
+ andi s0, s0, 7
+ addi s0, s0, -DCSR_CAUSE_DEBINT
+ bnez s0, spontaneous_halt
+
+jdebugram:
+ # Save s1 so that the debug program can use two registers.
+ csrr s0, MCPUID
+ bltz s0, save_not_32
+save_32:
+ sw s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
+ jr zero, DEBUG_RAM
+save_not_32:
+ slli s0, s0, 1
+ bltz s0, save_128
+save_64:
+ sd s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 8)(zero)
+ jr zero, DEBUG_RAM
+save_128:
+ nop #sq s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 16)(zero)
+ jr zero, DEBUG_RAM
+
+spontaneous_halt:
+ csrr s0, MHARTID
+ sw s0, SETHALTNOT(zero)
+ csrsi DCSR, DCSR_HALT_OFFSET
+
+wait_for_interrupt:
+ csrr s0, DCSR
+ andi s0, s0, (1<<DCSR_DEBUGINT_OFFSET)
+ beqz s0, wait_for_interrupt
+
+ j jdebugram
--- /dev/null
+static const unsigned char debug_rom_raw[] = {
+ 0x6f, 0x00, 0x40, 0x05, 0xf3, 0x24, 0x00, 0xf1, 0x23, 0x24, 0x90, 0x10,
+ 0xf3, 0x24, 0x00, 0x79, 0x93, 0xf4, 0x04, 0x40, 0x63, 0x94, 0x04, 0x08,
+ 0xf3, 0x24, 0x00, 0xf0, 0x63, 0xc6, 0x04, 0x00, 0x83, 0x24, 0xc0, 0x43,
+ 0x6f, 0x00, 0x80, 0x01, 0x93, 0x94, 0x14, 0x00, 0x63, 0xc6, 0x04, 0x00,
+ 0x83, 0x34, 0x80, 0x43, 0x6f, 0x00, 0x80, 0x00, 0x13, 0x00, 0x00, 0x00,
+ 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x84, 0x00, 0x63, 0x04, 0x04, 0x00,
+ 0x6f, 0x00, 0x40, 0x05, 0x73, 0x24, 0x20, 0x79, 0x73, 0x00, 0x00, 0x10,
+ 0x73, 0x10, 0x24, 0x79, 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x74, 0x00,
+ 0x13, 0x04, 0xd4, 0xff, 0x63, 0x16, 0x04, 0x02, 0x73, 0x24, 0x00, 0xf0,
+ 0x63, 0x46, 0x04, 0x00, 0x23, 0x2e, 0x90, 0x42, 0x67, 0x00, 0x00, 0x40,
+ 0x13, 0x14, 0x14, 0x00, 0x63, 0x46, 0x04, 0x00, 0x23, 0x3c, 0x90, 0x42,
+ 0x67, 0x00, 0x00, 0x40, 0x13, 0x00, 0x00, 0x00, 0x67, 0x00, 0x00, 0x40,
+ 0x73, 0x24, 0x00, 0xf1, 0x23, 0x20, 0x80, 0x10, 0x73, 0xe0, 0x01, 0x79,
+ 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x04, 0x40, 0xe3, 0x0c, 0x04, 0xfe,
+ 0x6f, 0xf0, 0x1f, 0xfc
+};
+static const unsigned int debug_rom_raw_len = 172;
--- /dev/null
+OUTPUT_ARCH( "riscv" )
+ENTRY( entry )
+SECTIONS
+{
+ . = 0xfffff800; /* TODO: 0x800 */
+ .text :
+ {
+ *(.text)
+ }
+ _end = .;
+}
+++ /dev/null
-static unsigned char debug_rom_raw[] = {
- 0x6f, 0x00, 0x40, 0x05, 0xf3, 0x24, 0x00, 0xf1, 0x23, 0x24, 0x90, 0x10,
- 0xf3, 0x24, 0x00, 0x79, 0x93, 0xf4, 0x04, 0x40, 0x63, 0x94, 0x04, 0x08,
- 0xf3, 0x24, 0x00, 0xf0, 0x63, 0xc6, 0x04, 0x00, 0x83, 0x24, 0xc0, 0x43,
- 0x6f, 0x00, 0x80, 0x01, 0x93, 0x94, 0x14, 0x00, 0x63, 0xc6, 0x04, 0x00,
- 0x83, 0x34, 0x80, 0x43, 0x6f, 0x00, 0x80, 0x00, 0x13, 0x00, 0x00, 0x00,
- 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x84, 0x00, 0x63, 0x04, 0x04, 0x00,
- 0x6f, 0x00, 0x40, 0x05, 0x73, 0x24, 0x20, 0x79, 0x73, 0x00, 0x00, 0x10,
- 0x73, 0x10, 0x24, 0x79, 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x74, 0x00,
- 0x13, 0x04, 0xd4, 0xff, 0x63, 0x16, 0x04, 0x02, 0x73, 0x24, 0x00, 0xf0,
- 0x63, 0x46, 0x04, 0x00, 0x23, 0x2e, 0x90, 0x42, 0x67, 0x00, 0x00, 0x40,
- 0x13, 0x14, 0x14, 0x00, 0x63, 0x46, 0x04, 0x00, 0x23, 0x3c, 0x90, 0x42,
- 0x67, 0x00, 0x00, 0x40, 0x13, 0x00, 0x00, 0x00, 0x67, 0x00, 0x00, 0x40,
- 0x73, 0x24, 0x00, 0xf1, 0x23, 0x20, 0x80, 0x10, 0x73, 0xe0, 0x01, 0x79,
- 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x04, 0x40, 0xe3, 0x0c, 0x04, 0xfe,
- 0x6f, 0xf0, 0x1f, 0xfc
-};
-static unsigned int debug_rom_raw_len = 172;
+++ /dev/null
-# Recursive make is bad, but in this case we're cross compiling which is a
-# pretty unusual use case.
-
-CC = $(RISCV)/bin/riscv64-unknown-elf-gcc
-OBJCOPY = $(RISCV)/bin/riscv64-unknown-elf-objcopy
-
-%.o: %.S
- $(CC) -c $<
-
-debug_rom.cc: debug_rom.raw
- xxd -i $^ > $@
-
-debug_rom.raw: debug_rom
- $(OBJCOPY) -O binary --only-section .text debug_rom debug_rom.raw
-
-debug_rom: debug_rom.o
- $(CC) -nostdlib -nostartfiles -Tlink.ld -o $@ $^
-
-clean:
- rm -f debug_rom debug_rom.o debug_rom.raw debug_rom.c
+++ /dev/null
-# This code should be functional. Doesn't have to be optimal.
-# I'm writing it to prove that it can be done.
-
-# TODO: Update these constants once they're finalized in the doc.
-
-#define DCSR 0x790
-#define DCSR_CAUSE_DEBINT 3
-#define DCSR_HALT_OFFSET 3
-#define DCSR_DEBUGINT_OFFSET 10
-
-#define DSCRATCH 0x792
-
-#define MCPUID 0xf00
-#define MHARTID 0xf10
-
-#define DEBUG_RAM 0x400
-#define DEBUG_RAM_SIZE 64
-
-#define SETHALTNOT 0x100
-#define CLEARHALTNOT 0x104
-#define CLEARDEBINT 0x108
-
- .global entry
- .global resume
-
- # Automatically called when Debug Mode is first entered.
-entry: j _entry
- # Should be called by Debug RAM code that has finished execution and
- # wants to return to Debug Mode.
-resume:
- # Clear debug interrupt.
-clear_debint:
- csrr s1, MHARTID
- sw s1, CLEARDEBINT(zero)
-clear_debint_loop:
- csrr s1, DCSR
- andi s1, s1, (1<<DCSR_DEBUGINT_OFFSET)
- bnez s1, wait_for_interrupt
-
- # Restore s1.
- csrr s1, MCPUID
- bltz s1, restore_not_32
-restore_32:
- lw s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
- j check_halt
-restore_not_32:
- slli s1, s1, 1
- bltz s1, restore_128
-restore_64:
- ld s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 8)(zero)
- j check_halt
-restore_128:
- nop #lq s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 16)(zero)
-
-check_halt:
- csrr s0, DCSR
- andi s0, s0, (1<<DCSR_HALT_OFFSET)
- beqz s0, exit
- j wait_for_interrupt
-
-exit:
- # Restore s0.
- csrr s0, DSCRATCH
- eret
-
-
-_entry:
- # Save s0 in DSCRATCH
- csrw DSCRATCH, s0
-
- # Check why we're here
- csrr s0, DCSR
- # cause is in bits 2:0 of dcsr
- andi s0, s0, 7
- addi s0, s0, -DCSR_CAUSE_DEBINT
- bnez s0, spontaneous_halt
-
-jdebugram:
- # Save s1 so that the debug program can use two registers.
- csrr s0, MCPUID
- bltz s0, save_not_32
-save_32:
- sw s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
- jr zero, DEBUG_RAM
-save_not_32:
- slli s0, s0, 1
- bltz s0, save_128
-save_64:
- sd s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 8)(zero)
- jr zero, DEBUG_RAM
-save_128:
- nop #sq s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 16)(zero)
- jr zero, DEBUG_RAM
-
-spontaneous_halt:
- csrr s0, MHARTID
- sw s0, SETHALTNOT(zero)
- csrsi DCSR, DCSR_HALT_OFFSET
-
-wait_for_interrupt:
- csrr s0, DCSR
- andi s0, s0, (1<<DCSR_DEBUGINT_OFFSET)
- beqz s0, wait_for_interrupt
-
- j jdebugram
+++ /dev/null
-extern unsigned char *debug_rom_raw;
-extern unsigned int debug_rom_raw_len;
+++ /dev/null
-OUTPUT_ARCH( "riscv" )
-ENTRY( entry )
-SECTIONS
-{
- . = 0xfffff800; /* TODO: 0x800 */
- .text :
- {
- *(.text)
- }
- _end = .;
-}
#include "config.h"
#include "common.h"
#include <cinttypes>
-#include "debug_rom.h"
+#include "debug_rom/debug_rom.h"
typedef int64_t sreg_t;
typedef uint64_t reg_t;