add bare-metal test image and update .gitignore

This commit is contained in:
Stefan 2021-08-17 09:37:49 +02:00
parent 30bd88dbbf
commit 9c936f211c
6 changed files with 261 additions and 0 deletions

4
.gitignore vendored
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@ -9,3 +9,7 @@ rust_payload/target
rust_payload/Cargo.lock
fw_payload.*
*.dtb
*.bmp
*.bin
*.elf
*.img

34
bare_metal_test/Makefile Normal file
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TARGET ?= bare
SRC_DIRS ?= .
PREFIX ?= ../buildroot-2021.05/output/host/bin/riscv32-buildroot-linux-gnu-
CC := $(PREFIX)cc
AS := $(PREFIX)as
LD := $(PREFIX)ld
OBJDUMP := $(PREFIX)objcopy
SRCS := $(wildcard *.S)
SRCS += $(wildcard *.c)
OBJS := $(addsuffix .o,$(basename $(SRCS)))
DEPS := $(OBJS:.o=.d)
INC_DIRS := $(shell find $(SRC_DIRS) -type d)
INC_FLAGS := $(addprefix -I,$(INC_DIRS))
CFLAGS += -O3 -march=rv32ima -mabi=ilp32 -fno-stack-protector -fno-pie
ASFLAGS += -march=rv32ima -mabi=ilp32
LDFLAGS += -static -nostdlib -nostartfiles -nodefaultlibs -Triscv32.ld -Wl,--no-as-needed
$(TARGET): $(OBJS)
$(CC) $(LDFLAGS) $(OBJS) -o $@ $(LOADLIBES) $(LDLIBS)
$(TARGET).img: $(TARGET)
riscv32-elf-objcopy -O binary $< $@
.PHONY: clean
clean:
$(RM) $(TARGET) $(OBJS) $(DEPS)
.PHONY: run
run: $(TARGET).img
../rvc -d ../dts.dtb -b $(TARGET).img

BIN
bare_metal_test/bare Executable file

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52
bare_metal_test/bare.c Normal file
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#include <stdbool.h>
#define UART_THR (*(volatile unsigned char*)0x10000000)
#define UART_LSR (*(volatile unsigned char*)0x10000005)
#define UART_LSR_THRE 0x20
// wait for Transfer Hold Register to clear, then write character to print it
void uart_putc(unsigned char c) {
while (UART_THR || !(UART_LSR & UART_LSR_THRE)) {}
UART_THR = c;
}
void print(const char* str) {
while (*str) {
uart_putc(*str++);
}
}
static bool got_ssip = false;
volatile static long long a = 0xaaaaffffffff;
// runs in supervisor mode via mideleg (machine-mode trap delegation)
void handle_trap(void) {
print("[bare/trap] got SSIP!\n");
got_ssip = true;
}
// called from assembly, runs in supervisor mode (via sret)
int main(void) {
print("[bare] in main()\n");
print("[bare] testing arithmetic...\n");
long long b = a * 400LLU * -1;
if (b != -0x10AAB2FFFFFFE70LL) {
print("[bare] got wrong result :(\n");
} else {
print("[bare] got correct result!\n");
}
print("[bare] testing trap handler...\n");
__asm volatile("csrw sip, 0x2");
while (!got_ssip) {}
print("[bare] selftest done!\n");
print("[bare] now go run something more exciting...\n");
while (true) {}
return 0;
}

137
bare_metal_test/init.S Normal file
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#define SLL32 sll
#define STORE sw
#define LOAD lw
#define LWU lw
#define LOG_REGBYTES 2
#define REGBYTES (1 << LOG_REGBYTES)
.section .entry, "ax", %progbits
.align 4
.globl _start
_start:
csrw mie, zero
csrw mip, zero
lla a3, _start_hang
csrw mtvec, a3
lla a3, _s_trap_entry
csrw stvec, a3
# enable supervisor software interrupt
li a3, 0x2
csrw sie, a3
csrw mie, a3
csrw mideleg, a3
li a3, 0x00b
csrs mstatus, a3
lla sp, _estack
lla a3, main
csrw mepc, a3
li a3, 0x800
csrs mstatus, a3
mret
j _start_hang
.section .entry, "ax", %progbits
.align 4
.globl _start_hang
_start_hang:
j _start_hang
.section .entry, "ax", %progbits
.align 4
.globl _trap_entry
_s_trap_entry:
addi sp,sp,-320
# save gprs
STORE x1,1*REGBYTES(x2)
STORE x3,3*REGBYTES(x2)
STORE x4,4*REGBYTES(x2)
STORE x5,5*REGBYTES(x2)
STORE x6,6*REGBYTES(x2)
STORE x7,7*REGBYTES(x2)
STORE x8,8*REGBYTES(x2)
STORE x9,9*REGBYTES(x2)
STORE x10,10*REGBYTES(x2)
STORE x11,11*REGBYTES(x2)
STORE x12,12*REGBYTES(x2)
STORE x13,13*REGBYTES(x2)
STORE x14,14*REGBYTES(x2)
STORE x15,15*REGBYTES(x2)
STORE x16,16*REGBYTES(x2)
STORE x17,17*REGBYTES(x2)
STORE x18,18*REGBYTES(x2)
STORE x19,19*REGBYTES(x2)
STORE x20,20*REGBYTES(x2)
STORE x21,21*REGBYTES(x2)
STORE x22,22*REGBYTES(x2)
STORE x23,23*REGBYTES(x2)
STORE x24,24*REGBYTES(x2)
STORE x25,25*REGBYTES(x2)
STORE x26,26*REGBYTES(x2)
STORE x27,27*REGBYTES(x2)
STORE x28,28*REGBYTES(x2)
STORE x29,29*REGBYTES(x2)
STORE x30,30*REGBYTES(x2)
STORE x31,31*REGBYTES(x2)
# get sr, epc, badvaddr, cause
csrr s0, sstatus
csrr t1, sepc
csrr t2, stval
csrr t3, scause
STORE t0, 2*REGBYTES(x2)
STORE s0, 32*REGBYTES(x2)
STORE t1, 33*REGBYTES(x2)
STORE t2, 34*REGBYTES(x2)
STORE t3, 35*REGBYTES(x2)
move a0, sp
jal handle_trap
mv a0, sp
addi sp, sp, 320
LOAD t0, 32*REGBYTES(a0)
LOAD t1, 33*REGBYTES(a0)
csrw sstatus, t0
csrw sepc, t1
# restore x registers
LOAD x1,1*REGBYTES(a0)
LOAD x2,2*REGBYTES(a0)
LOAD x3,3*REGBYTES(a0)
LOAD x4,4*REGBYTES(a0)
LOAD x5,5*REGBYTES(a0)
LOAD x6,6*REGBYTES(a0)
LOAD x7,7*REGBYTES(a0)
LOAD x8,8*REGBYTES(a0)
LOAD x9,9*REGBYTES(a0)
LOAD x11,11*REGBYTES(a0)
LOAD x12,12*REGBYTES(a0)
LOAD x13,13*REGBYTES(a0)
LOAD x14,14*REGBYTES(a0)
LOAD x15,15*REGBYTES(a0)
LOAD x16,16*REGBYTES(a0)
LOAD x17,17*REGBYTES(a0)
LOAD x18,18*REGBYTES(a0)
LOAD x19,19*REGBYTES(a0)
LOAD x20,20*REGBYTES(a0)
LOAD x21,21*REGBYTES(a0)
LOAD x22,22*REGBYTES(a0)
LOAD x23,23*REGBYTES(a0)
LOAD x24,24*REGBYTES(a0)
LOAD x25,25*REGBYTES(a0)
LOAD x26,26*REGBYTES(a0)
LOAD x27,27*REGBYTES(a0)
LOAD x28,28*REGBYTES(a0)
LOAD x29,29*REGBYTES(a0)
LOAD x30,30*REGBYTES(a0)
LOAD x31,31*REGBYTES(a0)
# restore a0 last
LOAD x10,10*REGBYTES(a0)
# gtfo
sret

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@ -0,0 +1,34 @@
MEMORY
{
RAM : ORIGIN = 0x80000000, LENGTH = 31M
}
_estack = ORIGIN(RAM) + LENGTH(RAM);
SECTIONS
{
.text :
{
. = ALIGN(4);
*(.entry)
*(.text)
*(.text*)
*(.rodata)
*(.rodata*)
} >RAM
.data :
{
. = ALIGN(4);
*(.data)
*(.data*)
} >RAM
.bss :
{
. = ALIGN(4);
*(.bss)
*(.bss*)
*(COMMON)
} >RAM
}