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/* green-eye uproc demo firmware.
*
* A small, deterministic "GSP-like" service:
* - gsp_ctrl global control block (magic 0x47535031) in .gsp_data;
* - mailbox-driven RPC dispatcher with a handler table;
* - handlers: PING, ECHO, FILL, SUM, STATE (4-stage machine), FAULT (ebreak);
* - a self-test sequence at boot so a freshly attached debugger sees events;
* - a free-running heartbeat so memory activity is always present.
*
* No libc: memcpy/memset are provided for the compiler.
*/
#include "ge_uart.h"
#define GSP_MAGIC 0x47535031u
typedef struct {
u32 magic; /* +0x00 */
u32 version; /* +0x04 */
u32 state; /* +0x08 */
u32 heartbeat; /* +0x0c */
u64 rpc_count; /* +0x10 */
u64 last_rpc; /* +0x18 */
u64 mailbox; /* +0x20 */
u64 arg0; /* +0x28 */
u64 arg1; /* +0x30 */
u64 result; /* +0x38 */
char buf[256]; /* +0x40 */
u64 handler_count; /* +0x140 */
u64 handlers[8]; /* +0x148 */
} gsp_ctrl_t;
volatile gsp_ctrl_t gsp_ctrl __attribute__((section(".gsp_data"), aligned(64)));
/* ---- compiler support (freestanding) ---- */
void *memcpy(void *dst, const void *src, u64 n)
{
u8 *d = (u8 *)dst;
const u8 *s = (const u8 *)src;
while (n--) {
*d++ = *s++;
}
return dst;
}
void *memset(void *dst, int value, u64 n)
{
u8 *d = (u8 *)dst;
while (n--) {
*d++ = (u8)value;
}
return dst;
}
static u64 strlen_local(const char *s)
{
u64 n = 0;
while (s[n]) {
n++;
}
return n;
}
/* ---- RPC handlers (kept as symbols for green-eye hooks) ---- */
__attribute__((noinline)) u64 rpc_ping(u64 a0, u64 a1)
{
(void)a1;
return a0 ^ 0xbeefu;
}
__attribute__((noinline)) u64 rpc_echo(u64 a0, u64 a1)
{
(void)a1;
const char *src = (const char *)a0;
u64 n = strlen_local(src);
if (n > sizeof(gsp_ctrl.buf) - 1) {
n = sizeof(gsp_ctrl.buf) - 1;
}
memcpy((void *)gsp_ctrl.buf, src, n);
gsp_ctrl.buf[n] = '\0';
return n;
}
__attribute__((noinline)) u64 rpc_fill(u64 a0, u64 a1)
{
u64 n = a1 > sizeof(gsp_ctrl.buf) ? sizeof(gsp_ctrl.buf) : a1;
memset((void *)gsp_ctrl.buf, (int)(a0 & 0xff), n);
return n;
}
__attribute__((noinline)) u64 rpc_sum(u64 a0, u64 a1)
{
const u8 *p = (const u8 *)a0;
u64 total = 0;
for (u64 i = 0; i < a1; i++) {
total += p[i];
}
return total;
}
__attribute__((noinline)) u64 rpc_state(u64 a0, u64 a1)
{
(void)a0;
(void)a1;
u64 stage = gsp_ctrl.state & 3u;
u64 out = 0;
switch (stage) {
case 0:
out = 0x10;
break;
case 1:
out = 0x20;
break;
case 2:
out = 0x30;
break;
default:
out = 0x40;
break;
}
gsp_ctrl.state = (u32)((stage + 1) & 3u);
return out;
}
__attribute__((noinline)) u64 rpc_fault(u64 a0, u64 a1)
{
(void)a0;
(void)a1;
__asm__ volatile("ebreak"); /* debugger trap: green-eye stops here */
return 0xdead;
}
/* ---- dispatcher ---- */
typedef u64 (*rpc_fn)(u64, u64);
void rpc_dispatch(u64 cmd, u64 a0, u64 a1)
{
u64 result;
switch (cmd) {
case 1:
result = rpc_ping(a0, a1);
break;
case 2:
result = rpc_echo(a0, a1);
break;
case 3:
result = rpc_fill(a0, a1);
break;
case 4:
result = rpc_sum(a0, a1);
break;
case 5:
result = rpc_state(a0, a1);
break;
case 6:
result = rpc_fault(a0, a1);
break;
default:
result = ~cmd;
break;
}
gsp_ctrl.result = result;
gsp_ctrl.last_rpc = cmd;
gsp_ctrl.rpc_count = gsp_ctrl.rpc_count + 1; /* after the handler */
}
static void install_handlers(void)
{
gsp_ctrl.handlers[0] = (u64)(unsigned long)rpc_ping;
gsp_ctrl.handlers[1] = (u64)(unsigned long)rpc_echo;
gsp_ctrl.handlers[2] = (u64)(unsigned long)rpc_fill;
gsp_ctrl.handlers[3] = (u64)(unsigned long)rpc_sum;
gsp_ctrl.handlers[4] = (u64)(unsigned long)rpc_state;
gsp_ctrl.handlers[5] = (u64)(unsigned long)rpc_fault;
gsp_ctrl.handler_count = 6;
}
int main(void)
{
volatile gsp_ctrl_t *ctl = &gsp_ctrl;
ctl->magic = GSP_MAGIC;
ctl->version = 1;
ctl->state = 0;
ctl->heartbeat = 0;
ctl->rpc_count = 0;
ctl->last_rpc = 0;
ctl->mailbox = 0;
ctl->result = 0;
ctl->buf[0] = '\0';
install_handlers();
uart_puts("GREEN-EYE UPROC DEMO v1\n");
uart_puts("MAGIC ");
uart_hex(ctl->magic, 8);
uart_puts(" CTRL@");
uart_hex((u64)(unsigned long)ctl, 8);
uart_puts("\n");
/* Deterministic self-test so freshly attached instrumentation sees events. */
rpc_dispatch(1, 0x1111, 0);
rpc_dispatch(2, (u64)(unsigned long)"hello-green-eye", 0);
rpc_dispatch(3, 0x5a, 32);
rpc_dispatch(4, (u64)(unsigned long)ctl->buf, 16);
rpc_dispatch(5, 0, 0);
rpc_dispatch(5, 0, 0);
rpc_dispatch(5, 0, 0);
uart_puts("SELFTEST DONE\n");
for (;;) {
ctl->heartbeat = ctl->heartbeat + 1;
u64 cmd = ctl->mailbox;
if (cmd != 0) {
ctl->mailbox = 0;
rpc_dispatch(cmd, ctl->arg0, ctl->arg1);
}
for (volatile int i = 0; i < 2000; i++) {
__asm__ volatile("");
}
}
}
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