diff options
Diffstat (limited to 'arch/riscv64/init')
| -rw-r--r-- | arch/riscv64/init/init.c | 148 | ||||
| -rw-r--r-- | arch/riscv64/init/start.S | 38 |
2 files changed, 0 insertions, 186 deletions
diff --git a/arch/riscv64/init/init.c b/arch/riscv64/init/init.c deleted file mode 100644 index a4fa696..0000000 --- a/arch/riscv64/init/init.c +++ /dev/null @@ -1,148 +0,0 @@ -/* SPDX-License-Identifier: copyleft-next-0.3.1 */ -/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */ - -/** - * @file init.c - * riscv64 'bootstrap', move actual kernel into place and jump to virtual - * memory. - */ - -#include <kmi/types.h> -#include <kmi/attrs.h> -#include <kmi/utils.h> -#include <kmi/vmem.h> -#include <arch/vmem.h> -#include <libfdt.h> - -#include "../kernel/csr.h" - -void flush_tlb_full() -{ - /** @todo could be nice to have a common set of features with kernel, - * but for now this is good enough. */ - __asm__ volatile ("sfence.vma\n" ::: "memory"); -} - -/** - * Create page table entry. - * Copy from \ref arch/riscv64/kernel/vmem.c. - * - * @param a Virtual address. - * @param f PTE flags. - */ -#define to_pte(a, f) (((a) >> 12) << 10 | (f)) - -/** - * Get RAM base address from fdt. - * @todo in case of multiple RAM banks, should try to just find one - * of them and let the kernel figure the rest out. Kernel doesn't currently - * support multiple RAM banks. - * - * @param fdt FDT pointer. - * @return Physical address of ram base. - */ -static pm_t __fdt_ram_base(void *fdt) -{ - int mem_offset = fdt_path_offset(fdt, "/memory"); - const void *mem_reg = fdt_getprop(fdt, mem_offset, "reg", NULL); - - struct cell_info ci = get_cellinfo(fdt, mem_offset); - return (pm_t)fdt_load_int_ptr(ci.addr_cells, mem_reg); -} - -/** - * Jump into virtual memory. - * - * @param load_addr Address where init has been loaded. - * @param ram_base RAM base. - */ -static void init_bootmem(uintptr_t load_addr, uintptr_t ram_base) -{ - /* set all flags on, especially A and D since MMUs are allowed to raise - * exceptions that we're not ready to handle if they're unset. */ - size_t flags = VM_V | VM_X | VM_R | VM_W | VM_D | VM_A; - - extern char *__kernel; - extern char *__kernel_size; - uintptr_t top = load_addr + (uintptr_t)&__kernel + - (uintptr_t)&__kernel_size; - - /* this could be risky, as we might overwrite some bits of initrd or fdt - * if they're allocated too close to the kernel payload. - * @todo Allocate root_branch statically? */ - struct vmem *root_branch = (struct vmem *)align_up(top, SZ_4K); - - /* direct mapping (temp) */ - for (size_t i = 0; i <= CSTACK_PAGE; ++i) - root_branch->leaf[i] = (struct vmem *)to_pte(TOP_PAGE_SIZE * i, - flags); - - /* kernel (also sort of direct mapping) */ - flags |= VM_G; - for (size_t i = KSTART_PAGE; i < IO_PAGE; ++i) - root_branch->leaf[i] = (struct vmem *)to_pte( - ram_base + TOP_PAGE_SIZE * (i - KSTART_PAGE), flags); - - /* kernel IO, map to 0 for now, will be updated in the future */ - root_branch->leaf[IO_PAGE] = (struct vmem *)to_pte(0, flags); - - uintmax_t mode = Sv39; - switch (DEFAULT_Sv_MODE) { - case Sv32: mode = SATP_MODE_Sv32; break; - case Sv39: mode = SATP_MODE_Sv39; break; - case Sv48: mode = SATP_MODE_Sv48; break; - default: break; - }; - - flush_tlb_full(); - csr_write(CSR_SATP, mode | ((uintptr_t)root_branch >> 12)); -} - -/** - * Relocate kernel proper. - * @param load_addr Address to where init has been loaded. - * Used in calculating kernel start address. - */ -static void move_kernel(uintptr_t load_addr) -{ - extern char *__kernel; - extern char *__kernel_size; - - size_t sz = (size_t)&__kernel_size; - char *src = load_addr + (char *)&__kernel; - char *dst = (char *)VM_KERN; - for (size_t i = 0; i < sz; ++i) - dst[i] = src[i]; -} - -/** - * Main driver for the init loader. - * - * @param fdt Global FDT pointer, provided by bootloader. - * @param load_addr Address to where init has been loaded. - */ -void init(void *fdt, pm_t load_addr) -{ - extern void jump_to_kernel(void *fdt, pm_t ram_base, void *k); - - pm_t ram_base = __fdt_ram_base(fdt); - - init_bootmem(load_addr, ram_base); - move_kernel(load_addr); - - jump_to_kernel(fdt, ram_base, (void *)VM_KERN); -} - -#if GENERIC_UBOOT -void init_go(int argc, char **argv, pm_t load_addr) -{ - if (argc != 2) - return; - - void *fdt = (void *)strtouintptr(argv[1]); - - /* fdt is passed as second argument, load address first but since we - * already have it due to our ingenious _start, no need to parse it */ - init(fdt, load_addr); -} -#endif diff --git a/arch/riscv64/init/start.S b/arch/riscv64/init/start.S deleted file mode 100644 index b6394f7..0000000 --- a/arch/riscv64/init/start.S +++ /dev/null @@ -1,38 +0,0 @@ -/* SPDX-License-Identifier: copyleft-next-0.3.1 */ -/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */ - -/* generic u-boot passes argc and argv as if we were a regular - * program, so our load address must be placed third. - * If we have a 'custom' u-boot with kmi support, the fdt - * will be passed to us directly, so the load address can go second. - */ -#if GENERIC_UBOOT -# define LOAD_REG a2 -# define INIT init_go -#else -# define LOAD_REG a1 -# define INIT init -#endif - -.section .init -.global _start -/* Entry point to the kernel loader. */ -_start: -/* get load address */ -auipc LOAD_REG, 0 -/* keep using bootloader stack for now */ -//li sp, PM_STACK_TOP -/* make sure there's no garbage in tp, important for id assignment */ -li tp, 0 -call INIT -// INIT shouldn't return, but if we do we might as well just jump back to u-boot -// or wherever -ret - -.section .text -.global jump_to_kernel -jump_to_kernel: -li sp, VM_STACK_TOP // load virtual stack address -li fp, 0 -li gp, 0 -jr a2 // jump to kernel |