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#include "mod_mem_map.h"
#include "../output/vga_character.h"
__asm__(".code16gcc\n");
struct bios_address_descriptor {
uint32_t base_addr_low;
uint32_t base_addr_high;
uint32_t length_low;
uint32_t length_high;
uint32_t type;
};
uint32_t bios_mem_map_range(uint32_t continuation);
void show_bios_mem_descriptor(struct bios_address_descriptor descriptor);
static struct bios_address_descriptor curr_address_descriptor;
void populate_memory_map(void) {
vga_graphics_newln();
vga_graphics_return();
vga_graphics_write_str("system_memory_map = ");
vga_graphics_newln();
vga_graphics_return();
uint32_t cont = 0;
do {
cont = bios_mem_map_range(cont);
//vga_graphics_int_hex(cont);
show_bios_mem_descriptor(curr_address_descriptor);
} while (cont != 0);
}
void show_bios_mem_descriptor(struct bios_address_descriptor descriptor) {
vga_graphics_write_str("descriptor: ");
vga_graphics_write_str(" base: 0x");
vga_graphics_int_hex(descriptor.base_addr_high);
vga_graphics_int_hex(descriptor.base_addr_low);
vga_graphics_write_str(" length: 0x");
vga_graphics_int_hex(descriptor.length_high);
vga_graphics_int_hex(descriptor.length_low);
vga_graphics_write_str(" ");
vga_graphics_int_hex(descriptor.type);
vga_graphics_return();
vga_graphics_newln();
}
uint32_t bios_mem_map_range(uint32_t continuation) {
// I know I really want the bottom 16 bits of this address. So no warning, thanks.
#pragma GCC diagnostic ignored "-Wpointer-to-int-cast"
uint16_t address_descriptor = (uint16_t)(&curr_address_descriptor);
#pragma GCC diagnostic pop
__asm__(
"push %%es \n"
"mov %0, %%ebx \n"
"mov $0xE820, %%eax \n"
"mov %1, %%di \n"
"mov $0, %%cx \n"
"mov %%cx, %%es \n"
"mov $0x14, %%ecx \n"
"mov $0x534d4150, %%edx \n"
"int $0x15 \n"
"mov %%ebx, %0 \n"
"pop %%es \n"
:"+r"(continuation)
:"r"(address_descriptor)
: "%eax", "%ebx", "%ecx", "%edx", "cc"
);
return continuation;
}
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