Rework syscall ABI.

Syscalls now accept two parameters, allowing for things like "int count = read(buf, len)"
Rather than providing safe signatures for syscalls, the user is now given helper functions to safely parse incoming values, c-strings and slices.
This commit is contained in:
Toby Jaffey 2025-12-09 21:51:35 +00:00
parent f046a590c0
commit 76fba39a21
28 changed files with 543 additions and 537 deletions

View file

@ -14,6 +14,7 @@
X(UVM32_ERR_HUNG) \
X(UVM32_ERR_INTERNAL_CORE) \
X(UVM32_ERR_INTERNAL_STATE) \
X(UVM32_ERR_ARGS) \
#define X(name) name,
typedef enum {
@ -28,42 +29,17 @@ typedef enum {
UVM32_EVT_END,
} uvm32_evt_typ_t;
typedef enum {
UVM32_SYSCALL_TYP_BUF_TERMINATED_WR, // data write from vm, NULL terminated string of bytes, in uvm32_evt_syscall_t.val.buf
UVM32_SYSCALL_TYP_VOID, // no data
UVM32_SYSCALL_TYP_U32_WR, // data write from vm, in uvm32_evt_syscall_t.val.u32
UVM32_SYSCALL_TYP_U32_RD, // data read from vm, expects response in uvm32_evt_syscall_t.val.u32p
} uvm32_syscall_typ_t;
typedef uint32_t uvm32_user_syscall_code_t;
// user supplied mapping from syscall to typed syscall
typedef struct {
uint32_t syscall;
uvm32_user_syscall_code_t code;
uvm32_syscall_typ_t typ;
} uvm32_mapping_t;
typedef struct {
uint8_t *ptr;
uint32_t len;
} uvm32_evt_syscall_buf_t;
typedef struct {
uvm32_syscall_typ_t typ;
uvm32_user_syscall_code_t code;
union {
uvm32_evt_syscall_buf_t buf;
uint32_t u32;
uint32_t *u32p;
} val;
} uvm32_evt_syscall_t;
typedef struct {
uvm32_err_t errcode;
const char *errstr;
} uvm32_evt_err_t;
typedef struct {
uint32_t code; // syscall number
uint32_t *ret;
uint32_t *params[2];
} uvm32_evt_syscall_t;
typedef struct {
uvm32_evt_typ_t typ;
union {
@ -90,16 +66,33 @@ typedef enum {
typedef struct {
uvm32_status_t status;
uvm32_err_t err;
struct MiniRV32IMAState* core; // points at end of memory
struct MiniRV32IMAState core;
uint8_t memory[UVM32_MEMORY_SIZE];
uvm32_evt_t ioevt; // for building up in callbacks
const uvm32_mapping_t *mappings;
uint32_t numMappings;
} uvm32_state_t;
void uvm32_init(uvm32_state_t *vmst, const uvm32_mapping_t *mappings, uint32_t numMappings);
void uvm32_init(uvm32_state_t *vmst);
bool uvm32_load(uvm32_state_t *vmst, uint8_t *rom, int len);
bool uvm32_hasEnded(const uvm32_state_t *vmst);
uint32_t uvm32_run(uvm32_state_t *vmst, uvm32_evt_t *evt, uint32_t instr_meter);
// convenience for getptr
typedef struct {
uint8_t *ptr;
uint32_t len;
} uvm32_evt_syscall_buf_t;
typedef enum {
ARG0,
ARG1,
RET
} uvm32_arg_t;
uint32_t uvm32_getval(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t);
const char *uvm32_getcstr(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t);
void uvm32_setval(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t, uint32_t val);
uvm32_evt_syscall_buf_t uvm32_getbuf(uvm32_state_t *vmst, uvm32_evt_t *evt, uvm32_arg_t argPtr, uvm32_arg_t argLen);
void uvm32_clearError(uvm32_state_t *vmst);
#endif