mirror of
https://gitlab.com/qemu-project/qboot.git
synced 2024-02-13 08:33:40 +08:00
c476b5c671
This simplifies the success case, which never has to manipulate the carry flag. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
123 lines
2.1 KiB
C
123 lines
2.1 KiB
C
asm(".code16gcc");
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#include <stddef.h>
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#include "bios.h"
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#include "segment.h"
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#include "ioport.h"
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#include "processor-flags.h"
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#include "e820.h"
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static inline void set_fs(uint16_t seg)
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{
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asm volatile("movw %0,%%fs" : : "rm" (seg));
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}
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static inline uint8_t rdfs8(unsigned long addr)
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{
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uint8_t v;
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asm volatile("addr32 movb %%fs:%1,%0" : "=q" (v) : "m" (*(uint8_t *)addr));
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return v;
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}
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static inline uint32_t rdfs32(unsigned long addr)
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{
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uint32_t v;
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asm volatile("addr32 movl %%fs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
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return v;
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}
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static inline uint16_t rdcs16(void *p)
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{
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uint32_t addr = ((uintptr_t) p) & 65535;
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uint16_t v;
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asm volatile("addr32 movw %%cs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
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return v;
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}
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uint16_t e820_seg;
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bioscall void e820_query_map(struct biosregs *regs)
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{
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uint32_t map_size;
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uint32_t ndx;
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set_fs(rdcs16(&e820_seg));
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ndx = regs->ebx;
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map_size = rdfs32(offsetof(struct e820map, nr_map));
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if (ndx < map_size) {
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uint32_t start;
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unsigned int i;
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uint8_t *p;
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start = offsetof(struct e820map, map[ndx]);
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p = (void *) regs->edi;
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for (i = 0; i < sizeof(struct e820entry); i++)
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*p++ = rdfs8(start + i);
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}
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regs->eax = SMAP;
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regs->ecx = sizeof(struct e820entry);
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regs->ebx = ++ndx;
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if (ndx >= map_size)
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regs->ebx = 0; /* end of map */
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}
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bioscall void int15_handler(struct biosregs *regs)
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{
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switch (regs->eax) {
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case 0xe820:
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e820_query_map(regs);
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break;
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default:
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/* Set CF to indicate failure. */
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regs->eflags |= X86_EFLAGS_CF;
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break;
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}
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}
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/*
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* It's probably much more useful to make this print to the serial
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* line rather than print to a non-displayed VGA memory
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*/
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static inline void int10_putchar(struct biosregs *args)
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{
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uint8_t al = args->eax & 0xFF;
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outb(0x3f8, al);
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}
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#define VBE_STATUS_OK 0x004F
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#define VBE_STATUS_FAIL 0x014F
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static void int10_vesa(struct biosregs *args)
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{
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args->eax = VBE_STATUS_FAIL;
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}
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bioscall void int10_handler(struct biosregs *args)
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{
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uint8_t ah;
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ah = (args->eax & 0xff00) >> 8;
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switch (ah) {
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case 0x0e:
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int10_putchar(args);
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break;
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case 0x4f:
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int10_vesa(args);
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break;
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}
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}
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