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cc_amd64.S: implement user stack.

This commit is contained in:
Andrius Štikonas 2022-10-02 14:33:41 +01:00
parent b46ba0d078
commit d6d8b2b707
1 changed files with 44 additions and 3 deletions
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47
amd64/Development/cc_amd64.S
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@ -116,21 +116,29 @@ loop_options_done:
call [rcx+8] # rootdir->open()
add rsp, 48 # deallocate stack
# Allocate ourselves 64 MiB of memory
mov rdx, 0x4000000 # allocate 64 MiB of memory for malloc pool
# Allocate ourselves 16 MiB of memory
mov rdx, 0x1000000 # allocate 16 MiB of memory for malloc pool
call allocate_pool # allocate memory
mov [rip+malloc_pointer], rax # save malloc pointer
mov [rip+malloc_pool], rax # save the beginning of malloc pool
# Zero allocated memory buffer
add rax, 0x4000000 # end of malloc area
add rax, 0x1000000 # end of malloc area
zero_loop:
dec rax # next byte
mov BYTE PTR [rax], 0 # zero it
cmp rax, [rip+malloc_pointer] # if we are not done yet
jne zero_loop # then continue looping
# cc_amd64 needs quite a lot of stack space when building M2-Planet
# which is not guaranteed to be available on UEFI (it guarantees at least 128 KiB).
# Therefore we will allocate an extra space on heap and use part of it for user stack
mov rax, 0x400000 # Allocate 4 MiB for user stack
call malloc
mov [rip+user_stack], rax # Save user stack
call exit_uefi_stack # Switch to user stack
mov r15, 0 # Not writing to stderr yet
call fix_types # Resolve relative addresses in types struct to absolute
@ -165,6 +173,8 @@ Done_1:
# Free pool
push rax # save exit code
call enter_uefi_stack # Switch back to UEFI stack
mov rcx, [rip+malloc_pool] # arg1 = malloc_pool
call free_pool # system->boot->free_pool(malloc_pool)
@ -4585,6 +4595,28 @@ free_pool:
pop rax # deallocate stack
ret
# Switch to uefi stack
# does not change any other registers
enter_uefi_stack:
mov [rip+temp_rax], rax # save RAX
pop rax # Save return address
mov [rip+user_stack], rsp # save user stack
mov rsp, [rip+uefi_stack] # restore system stack
push rax # Restore return address
mov rax, [rip+temp_rax] # restore RAX
ret
# Switch to user stack
# does not change any other registers
exit_uefi_stack:
mov [rip+temp_rax], rax # save RAX
pop rax # Save return address
mov rsp, [rip+user_stack] # restore user stack
mov [rip+uefi_stack], rsp # save system stack
push rax # Restore return address
mov rax, [rip+temp_rax] # restore RAX
ret
# debug_list function
# Receives struct token_list* in RAX
# Prints contents of list and exits
@ -4855,6 +4887,15 @@ malloc_pool:
malloc_pointer:
.quad 0
uefi_stack:
.quad 0
user_stack:
.quad 0
temp_rax:
.quad 0
fin:
.quad 0