f3c7ac9696
Instead of using the bootsector to load a bootloader, just put the bootloader in the ROM and call it a day. It looks for a file on the SD card in the root directory named `kernel.bin` and loads it into memory. This is not a perfect solution, as the kernel will grow larger and the kernel load address will have to change. At this point I could add back the bootloader, but that is for later. Also the bootloader is just a copy of the kernel, so that can be trimmed down a lot.
62 lines
1.1 KiB
C
62 lines
1.1 KiB
C
#include <stdint.h>
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#include <conio.h>
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#include <string.h>
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#include "filesystem/fat.h"
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#include "filesystem/o65.h"
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void exec(char* filename) {
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o65_header_t* header;
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o65_opt_t* o65_opt;
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uint8_t* seg_ptr;
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uint8_t* code_base;
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uint8_t* data_base;
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uint16_t code_len;
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uint16_t data_len;
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uint8_t (*exec)(void);
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uint8_t ret;
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fat_read(filename, fat_buf);
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header = (o65_header_t*)fat_buf;
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if (header->c64_marker == O65_NON_C64 &&
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header->magic[0] == O65_MAGIC_0 &&
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header->magic[1] == O65_MAGIC_1 &&
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header->magic[2] == O65_MAGIC_2) {
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code_base = (uint8_t*)header->tbase;
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data_base = (uint8_t*)header->dbase;
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code_len = header->tlen;
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data_len = header->dlen;
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o65_opt = (o65_opt_t*)(fat_buf + sizeof(o65_header_t));
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while (o65_opt->olen)
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{
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o65_print_option(o65_opt);
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o65_opt = (o65_opt_t*)((uint8_t*)o65_opt + o65_opt->olen);
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}
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seg_ptr = (uint8_t*)o65_opt + 1;
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memcpy((uint8_t*)code_base, seg_ptr, code_len);
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seg_ptr+=code_len;
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memcpy((uint8_t*)data_base, seg_ptr, data_len);
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exec = (uint8_t (*)(void))code_base;
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ret = 0;
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ret = (*exec)();
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cprintf("ret: %x\n", ret);
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}
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}
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