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.
76 lines
1.3 KiB
C
76 lines
1.3 KiB
C
#include <stdint.h>
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#include <conio.h>
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#include "devices/sd_card.h"
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void sd_init() {
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uint32_t resp;
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sd_card_command(0, 0);
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sd_card_command(0x000001aa, 8);
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sd_card_resp(&resp);
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cprintf("CMD8: %lx\n", resp);
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sd_card_command(0, 55);
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sd_card_command(0x40180000, 41);
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sd_card_resp(&resp);
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cprintf("CMD41: %lx\n", resp);
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sd_card_command(0, 55);
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sd_card_command(0x40180000, 41);
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sd_card_resp(&resp);
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cprintf("CMD41: %lx\n", resp);
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sd_card_command(0, 2);
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sd_card_resp(&resp);
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cprintf("CMD2: %lx\n", resp);
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}
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uint16_t sd_get_rca() {
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uint32_t resp;
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sd_card_command(0, 3);
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resp = 0;
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sd_card_resp(&resp);
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//cprintf("CMD3: %lx\n", resp);
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return resp >> 16;
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}
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uint16_t sd_select_card(uint16_t rca) {
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uint32_t resp;
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sd_card_command((uint32_t)rca << 16, 7);
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sd_card_resp(&resp);
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return (uint16_t) resp;
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}
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uint16_t sd_get_status(uint16_t rca) {
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uint32_t resp;
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sd_card_command((uint32_t)rca << 16, 13);
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sd_card_resp(&resp);
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return (uint16_t) resp;
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}
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void sd_readblock(uint32_t addr, void* buf) {
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uint32_t resp;
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int i;
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sd_card_command(addr, 17);
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sd_card_resp(&resp);
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//cprintf("CMD17: %lx\n", resp);
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sd_card_wait_for_data();
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//cprintf("Read data: \n");
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for (i = 0; i < 512; i++){
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((uint8_t*)buf)[i] = sd_card_read_byte();
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}
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//cprintf("\n");
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}
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