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[metal] Allow programs larger than 440 KiB to run in bare metal mode (#685)

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* [metal] Copy program pages to extended memory at startup
* [metal] Reclaim base memory pages for later app use
* [metal] Load program pages beyond 1st 440 KiB to extended memory

o//examples/hellolua.com now runs correctly under QEMU (in
legacy BIOS mode).

* [metal] Place GDT in read/write segment

The CPU absolutely needs to alter the GDT when loading the
task register (via ltr).  To account for this, I move the
GDT into a read/write data section.  There is still a "rump"
read-only GDT in the text section that is used by the real
mode bootloader.

We also delay the loading of the task register (ltr) until
after the IDT and TSS are finally set up.

* [metal] Get examples/vga2.c serial output working for UEFI boot
* [metal] Get examples/vga2.c VGA output working for UEFI boot
* [metal] Allow munmap() to reclaim dynamically allocated pages
* Place TLS sections right after .text, not after embedded zip file

Co-authored-by: tkchia <tkchia-cosmo@gmx.com>
This commit is contained in:
tkchia 2022-12-18 09:51:20 +08:00 • committed by GitHub
parent 120079b0a6
commit 0da47c51de
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16 changed files with 725 additions and 191 deletions
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13
libc/runtime/pc.internal.h
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@ -167,6 +167,9 @@
#define PAGE_GROD /* blinkenlights MAP_GROWSDOWN */ 0b010000000000
#define PAGE_TA 0x00007ffffffff000
#define PAGE_PA2 0x00007fffffe00000
#define PAGE_IGN2 0x07f0000000000000
#define PAGE_REFC PAGE_IGN2 /* libc reference counting */
#define PAGE_1REF 0x0010000000000000 /* libc reference counting */
#define PAGE_XD 0x8000000000000000
#if !(__ASSEMBLER__ + __LINKER__ + 0)
@ -186,9 +189,13 @@ struct IdtDescriptor {
uint64_t *__get_virtual(struct mman *, uint64_t *, int64_t, bool);
uint64_t __clear_page(uint64_t);
uint64_t __new_page(struct mman *);
void __invert_memory_area(struct mman *, uint64_t *, uint64_t, uint64_t,
uint64_t);
void __map_phdrs(struct mman *, uint64_t *, uint64_t);
uint64_t * __invert_memory_area(struct mman *, uint64_t *, uint64_t, uint64_t,
uint64_t);
void __map_phdrs(struct mman *, uint64_t *, uint64_t, uint64_t);
void __reclaim_boot_pages(struct mman *, uint64_t, uint64_t);
void __ref_page(struct mman *, uint64_t *, uint64_t);
void __ref_pages(struct mman *, uint64_t *, uint64_t, uint64_t);
void __unref_page(struct mman *, uint64_t *, uint64_t);
forceinline unsigned char inb(unsigned short port) {
unsigned char al;