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#include "vm.h"
#include "mtrap.h"
#include "devicetree.h"
volatile uint32_t booted_harts_mask;
uintptr_t mem_size;
uint32_t num_harts;
static void mstatus_init()
{
if (!supports_extension('S'))
panic("supervisor support is required");
uintptr_t ms = 0;
ms = INSERT_FIELD(ms, MSTATUS_VM, VM_CHOICE);
ms = INSERT_FIELD(ms, MSTATUS_FS, 1);
write_csr(mstatus, ms);
ms = read_csr(mstatus);
if (EXTRACT_FIELD(ms, MSTATUS_VM) != VM_CHOICE)
have_vm = 0;
write_csr(mtimecmp, 0);
clear_csr(mip, MIP_MSIP);
write_csr(mie, -1);
}
static void delegate_traps()
{
uintptr_t interrupts = MIP_SSIP | MIP_STIP;
uintptr_t exceptions =
(1U << CAUSE_MISALIGNED_FETCH) |
(1U << CAUSE_FAULT_FETCH | CAUSE_BREAKPOINT) |
(1U << CAUSE_FAULT_LOAD) |
(1U << CAUSE_FAULT_STORE) |
(1U << CAUSE_BREAKPOINT) |
(1U << CAUSE_USER_ECALL);
write_csr(mideleg, interrupts);
write_csr(medeleg, exceptions);
kassert(read_csr(mideleg) == interrupts);
kassert(read_csr(medeleg) == exceptions);
}
static void memory_init()
{
if (mem_size == 0)
panic("could not determine memory capacity");
if ((intptr_t)mem_size < 0)
mem_size = INTPTR_MIN;
if (num_harts == 0)
panic("could not determine number of harts");
}
static void fp_init()
{
kassert(read_csr(mstatus) & MSTATUS_FS);
#ifdef __riscv_hard_float
if (!supports_extension('D'))
panic("FPU not found; recompile pk with -msoft-float");
for (int i = 0; i < 32; i++)
init_fp_reg(i);
write_csr(fcsr, 0);
#else
if (supports_extension('D'))
panic("FPU unexpectedly found; recompile pk without -msoft-float");
#endif
}
void hls_init(uint32_t id, uintptr_t* csrs)
{
hls_t* hls = OTHER_HLS(id);
memset(hls, 0, sizeof(*hls));
hls->hart_id = id;
hls->csrs = csrs;
hls->console_ibuf = -1;
if (id != 0) {
while (((booted_harts_mask >> id) & 1) == 0)
;
mb();
// wake up the hart by granting it a stack
csrs[CSR_MSCRATCH] = (uintptr_t)(OTHER_STACK_TOP(id) - MENTRY_FRAME_SIZE);
}
}
static void hart_init()
{
mstatus_init();
fp_init();
delegate_traps();
}
void init_first_hart()
{
file_init();
hart_init();
memset(HLS(), 0, sizeof(*HLS()));
parse_device_tree();
struct mainvars arg_buffer;
struct mainvars *args = parse_args(&arg_buffer);
memory_init();
vm_init();
request_htif_keyboard_interrupt();
boot_loader(args);
}
void init_other_hart()
{
hart_init();
// wait until virtual memory is enabled
while (*(pte_t* volatile*)&root_page_table == NULL)
;
mb();
write_csr(sptbr, (uintptr_t)root_page_table >> RISCV_PGSHIFT);
boot_other_hart();
}
void prepare_supervisor_mode()
{
uintptr_t mstatus = read_csr(mstatus);
mstatus = INSERT_FIELD(mstatus, MSTATUS_MPP, PRV_S);
mstatus = INSERT_FIELD(mstatus, MSTATUS_MPIE, 0);
write_csr(mstatus, mstatus);
write_csr(mscratch, MACHINE_STACK_TOP() - MENTRY_FRAME_SIZE);
}
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