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#include <comus/cpu.h>
#include <comus/syscalls.h>
#include <comus/drivers/acpi.h>
#include <comus/drivers/gpu.h>
#include <comus/drivers/pit.h>
#include <comus/memory.h>
#include <comus/procs.h>
#include <stdint.h>
#define RET(type, name) type *name = (type *)(¤t_pcb->regs->rax)
#define ARG1(type, name) type name = (type)(current_pcb->regs->rdi)
#define ARG2(type, name) type name = (type)(current_pcb->regs->rsi)
#define ARG3(type, name) type name = (type)(current_pcb->regs->rdx)
#define ARG4(type, name) type name = (type)(current_pcb->regs->rcx)
__attribute__((noreturn))
static int sys_exit(void)
{
ARG1(int, status);
current_pcb->exit_status = status;
pcb_zombify(current_pcb);
current_pcb = NULL;
// call next process
dispatch();
}
static int sys_write(void)
{
ARG1(int, fd);
ARG2(const void *, buffer);
ARG3(size_t, nbytes);
const char *map_buf = kmapuseraddr(current_pcb->memctx, buffer, nbytes);
if (map_buf == NULL)
return 0;
// cannot write to stdin
if (fd == 0)
nbytes = 0;
// write to stdout
else if (fd == 1) {
for (size_t i = 0; i < nbytes; i++)
kputc(map_buf[i]);
}
// files
else {
// TODO: write to files
nbytes = 0;
}
kunmapaddr(map_buf);
return nbytes;
}
__attribute__((noreturn))
static int sys_poweroff(void)
{
// TODO: we should probably
// kill all user processes
// and then sync the fs
acpi_shutdown();
}
static int sys_drm(void)
{
ARG1(void **, res_fb);
ARG2(int *, res_width);
ARG3(int *, res_height);
ARG4(int *, res_bpp);
void *pADDR, *vADDR;
int width, height, bpp;
size_t len;
if (gpu_dev == NULL)
return 1;
len = gpu_dev->width * gpu_dev->height * gpu_dev->bit_depth / 8;
pADDR =
mem_get_phys(kernel_mem_ctx, (void *)(uintptr_t)gpu_dev->framebuffer);
if (pADDR == NULL)
return 1;
vADDR = mem_mapaddr(current_pcb->memctx, pADDR, (void *)0x1000000000, len,
F_PRESENT | F_WRITEABLE | F_UNPRIVILEGED);
if (vADDR == NULL)
return 1;
width = gpu_dev->width;
height = gpu_dev->height;
bpp = gpu_dev->bit_depth;
mem_ctx_switch(current_pcb->memctx);
*res_fb = vADDR;
*res_width = width;
*res_height = height;
*res_bpp = bpp;
mem_ctx_switch(kernel_mem_ctx);
return 0;
}
static int sys_ticks(void)
{
RET(uint64_t, res_ticks);
*res_ticks = ticks;
return 0;
}
static int (*syscall_tbl[N_SYSCALLS])(void) = {
[SYS_exit] = sys_exit, [SYS_waitpid] = NULL,
[SYS_fork] = NULL, [SYS_exec] = NULL,
[SYS_open] = NULL, [SYS_close] = NULL,
[SYS_read] = NULL, [SYS_write] = sys_write,
[SYS_getpid] = NULL, [SYS_getppid] = NULL,
[SYS_gettime] = NULL, [SYS_getprio] = NULL,
[SYS_setprio] = NULL, [SYS_kill] = NULL,
[SYS_sleep] = NULL, [SYS_brk] = NULL,
[SYS_sbrk] = NULL, [SYS_poweroff] = sys_poweroff,
[SYS_drm] = sys_drm, [SYS_ticks] = sys_ticks,
};
void syscall_handler(struct cpu_regs *regs)
{
uint64_t num;
int (*handler)(void);
int ret = 1;
// make sure were in the kernel memory context
mem_ctx_switch(kernel_mem_ctx);
// update data
current_pcb->regs = regs;
num = current_pcb->regs->rax;
current_pcb->regs->rax = 0;
// check for invalid syscall
if (num >= N_SYSCALLS) {
// kill process
current_pcb->exit_status = 1;
pcb_zombify(current_pcb);
current_pcb = NULL;
// call next process
dispatch();
}
// run syscall handler
handler = syscall_tbl[num];
if (handler != NULL)
ret = handler();
// on failure, set rax
if (ret)
current_pcb->regs->rax = ret;
// return to current pcb
}
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